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Hiroki Nagai

Section

Institute of Fluid Science

Job title

Professor

Degree

博士（工学）（筑波大学）
修士（工学）（筑波大学）

researchmap

https://researchmap.jp/read0163102

J-GLOBAL ID

200901059591949732

Research History 7

2016/04 - Present

東北大学流体科学研究所　教授
2014/10 - 2015/09

Jet Propulsion Laboratory, California Institute of Technology　Visiting Researcher
2008/10 - 2015/03

東北大学大学院工学研究科　准教授
2007/04 - 2008/10

東北大学大学院工学研究科　助教
2004/04 - 2007/03

東北大学大学院工学研究科　助手
2001/04 - 2004/03

Japan Aerospace Exploration Agency　宇宙航空プロジェクト研究員
2000/04 - 2001/03

Institute of Engineering Mechanics and Systems　日本学術振興会特別研究員

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Education 2

University of Tsukuba　Graduate School, Division of Engineering　Institute of Engineering Mechanics and Systems

- 2000/03
University of Tsukuba

- 1995/03/24

Committee Memberships 27

一般社団法人日本流体力学会　理事

2022/02 - Present
一般社団法人可視化情報学会　代議員

2019/06 - Present
一般社団法人日本航空宇宙学会　宇宙システム・技術部門委員

2019/04 - Present
国立研究開発法人宇宙航空研究開発機構宇宙科学研究所　宇宙工学委員会委員

2019/04 - Present
一般社団法人日本航空宇宙学会　人材育成委員会委員

2017/04 - Present
宇宙航空研究開発機構　宇宙科学本部工学委員会

2011/04 - Present
可視化情報学会 PSP/TSP研究会　委員

2010/10 - Present
火星探査航空機WG　副主査

2010/04 - Present
一般社団法人日本航空宇宙学会　会誌理事

2022/04 - 2024/03
国立研究開発法人宇宙航空研究開発機構　宇宙探査イノベーションハブアドバイザリーボード専門委員

2022/01 - 2022/05
国立研究開発法人宇宙航空研究開発機構　宇宙探査イノベーションハブアドバイザリーボード専門委員

2020/07 - 2021/03
日本混相流学会　評議員

2019/08 - 2020/08
一般社団法人日本流体力学会　代議員

2018/04 - 2020/03
一般社団法人日本機械学会流体工学部門　運営委員

2017/04 - 2019/04
国立研究開発法人宇宙航空研究開発機構研究開発部門　客員研究員

2016/04 - 2017/03
日本航空宇宙学会北部支部　幹事

2007/04 - 2016/03
日本航空宇宙学会空力部門委員会　委員

2010/04 - 2014/03
日本機械学会宇宙工学部門　委員

2009/04 - 2014/03
可視化情報学会論文編集委員会　委員

2011/09 - 2013/09
日本機械学会マイクロ気体流れに関する調査研究分科会　委員

2011/04 - 2013/03
宇宙航空研究開発機構宇宙ミッション本部　客員研究員

2009/04 - 2011/03
宇宙航空研究開発機構総合技術研究本部　客員研究員

2006/04 - 2011/03
宇宙航空研究開発機構宇宙科学本部科学衛星専門委員会熱制御班　班員

2005/09 - 2011/03
日本航空宇宙学会北部支部20周年記念講演会　実行委員

2006/04 - 2007/03
第21回航空宇宙試験設備における計測に関する国際会議　企画運営委員会委員

2004/10 - 2005/12
学際領域分子イメージング技術に関する国際ワークショップ　企画運営委員会委員

2004/06 - 2004/12
平成13年度衝撃波シンポジウム　実行委員

2001/10 - 2002/03

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Professional Memberships 7

日本ヒートパイプ協会

2019 -
The Japanese Society for Multiphase Flow
The Visualization Scoiety of Japan
Japan Society of Fluid Mechanics
The Japan Society of Mechanical Engineers
American Institute of Aeronautics and Astronautics
Aeronautical and Space Sciences Japan

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Research Interests 15

Low Reynolds number
Transonic
Supersonic
Functional molecular sensor
Aerodynamic heating
Re-entry capsule
Shock wave
Superfluid
Aerodynamics
Self Oscillating
Thermal control
Heat Pipe
Thermofluid dynamics
Pressure-Sensitive Paint
Mars Air Plane

Research Areas 3

Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Fluid engineering /
Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Thermal engineering /
Aerospace, marine, and maritime Engineering / Aerospace engineering / Aerospace Engineering

Awards 15

総長賞

2023/03　東北大学
Best Poster Presentation Awasrd

2023/03　The 22nd International Symposium on Advanced Fluid Information IFS Collaborative Research Forum　Geometrically Nonlinear Beam Model for Slender Multibody Wings
第33期学会賞奨励賞

2022/08　可視化情報学会　PSP/TSP計測とデータ駆動型解析の組合せによる非定常流れ場の解明
Best Presentation Awards

2022/08　The 13th Pacific Symposium on Flow Visualization and Image Processing　FREQUENCY RESPONSE OF CARBON-NANOTUBE TEMPERATURE-SENSITIVE PAINT
独創研究学生賞

2022/03　日本機械学会東北支部　遷音速で自由飛行する物体表面の革新的圧力分布計測技術の研究
第47回可視化情報シンポジウムベストプレゼンテーション賞

2021/09　可視化情報学会　低速風洞での流れ場計測におけるcntTSPの応答性評価
優秀講演賞

2021/08　日本航空宇宙学会　遷音速自由飛行する次世代再突入カプセルの流れ場と飛行特性
大学院研究奨励賞

2021/03　自動車技術会
総長賞

2021/03　東北大学
Good Presentation Award for Student

2021/03　Nothern Branch of the Japan Society for Aeronautical and Space Sciences　Visualization of the Flow Field Around the Next Generation Re-entry Capsule at Low Velocity
第48回可視化情報シンポジウムベストプレゼンテーション賞

2020/09　可視化情報学会　非定常PSP計測における動的モード分解のデータ取得条件の調査
日本機械学会論文賞

2017/04　日本機械学会　マルチエバポレータ型ループヒートパイプの内部流動特性に関する研究（微小重力環境下での蒸発器及び凝縮器の可視化）
Poster Session Second Prize, 28th International Symposium on Space Technology and Science

2011/06/11　International Symposium on Space Technology and Science
第20期可視化情報学会学会賞（論文賞）

2009/07　（社）可視化情報学会
Student Meritorious Paper Award

1999/07/13　Cryogenic Scoiety of USA

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Papers 131

Study on flow patterns of low mass flux condensate flow inside a nitrogen-charged cryogenic loop heat pipe

Atsuhiro Gomi, Kimihide Odagiri, Hiroki Nagai, Hiroyuki Ogawa

International Journal of Heat and Mass Transfer　2025/09

DOI： 10.1016/j.ijheatmasstransfer.2025.127124 　
Operating characteristics comparison in a loop heat pipe with two evaporators and two condensers and a dual loop heat pipes network under thermal vacuum environment Peer-reviewed

Xinyu Chang, Yasuko Shibano, Hiroyuki Ogawa, Hiroki Nagai, Hosei Nagano

Applied Thermal Engineering　126565-126565　2025/04
Publisher: Elsevier BV
DOI： 10.1016/j.applthermaleng.2025.126565 　

ISSN： 1359-4311
Thrust variations in small rotors due to corner and vertex effects on the ground side Peer-reviewed

H. Otsuka, S. Akaba, T. Hara, H. Nagai, H. Tokutake

The Aeronautical Journal　2025/04

DOI： 10.1017/aer.2024.148 　
Impulsive force measurement by fast response pressure-sensitive paint during shock wave passage Peer-reviewed

T. Ikami, J. Abe, S. Tamakuma, S. Takahashi, H. Nagai

Shock Waves　2025/03/24
Publisher: Springer Science and Business Media LLC
DOI： 10.1007/s00193-025-01221-9 　

ISSN： 0938-1287

eISSN： 1432-2153

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Abstract The interaction between a shock wave and an object causes an impulsive force on the object that lasts for a very short time on the order of milliseconds. This study proposes impulsive force measurements using anodized aluminum pressure-sensitive paint (AA-PSP), which is an optical pressure measurement technique. The response time of AA-PSP is on the order of microseconds, indicating the potential for fast pressure drag measurements by integrating the pressure distribution on the surface. In this study, at first, the response time of the fabricated AA-PSP is measured and determined to be $$3.3~\upmu \hbox {s}$$ . A cylindrical model coated with the AA-PSP is installed at the outlet of a shock tube, and the surface pressure is measured in order to calculate the pressure drag with a time resolution of $$10~\upmu \hbox {s}$$ . The experimental results are compared with an Euler CFD simulation computed using an in-house code. The maximum pressure drag in the numerical result exceeds that in the experimental result; however, the maximum pressure drag timings are in good quantitative agreement. In addition to measuring the impulsive force, the AA-PSP results allow for the visualization of complex flow phenomena, such as diffraction and decay in the shock wave strength. This simultaneous measurement of the flow field and impulsive forces can deepen the understanding of the relationship between them.
High-luminescence polymer/ceramic pressure-sensitive paint employing low-refractive-index silica nanoparticles

Masaki Okawa, Tsubasa Ikami, Yuma Yamagishi, Kanako Watanabe, Hiroki Nagai

Measurement Science and Technology　36　(3)　035104-035104　2025/02/11
Publisher: IOP Publishing
DOI： 10.1088/1361-6501/adb065 　

ISSN： 0957-0233

eISSN： 1361-6501

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Abstract Pressure-sensitive paint (PSP) is an optical pressure-measurement technique that uses oxygen quenching. In unsteady PSP measurements, PSPs necessitate not only pressure sensitivity and response speed but also higher luminescence intensity. In this study, spherical silica nanoparticles are mixed into the paint to achieve a brighter luminescence. We prototype PSPs using particle size and mixing ratio as parameters and evaluate their performance. The results exhibit the luminescence intensity changes due to the low refractive index of silica; the smaller the particle size and the higher the particle ratio, the stronger the luminescence intensity. Silica-based PSPs are approximately 1.5 times brighter than titania-based PSP; which have frequently been used in previous studies. Additionally, a comprehensive performance investigation indicates that the silica-based PSP with the brightest formulation has a pressure sensitivity of 0.72 %/kPa with a response speed of 11.0 µs. These results prove that the higher luminescence is compatible with the high sensitivity and fast response using low-refractive index nanoparticles.
Unsteady Propeller Wake Interference on Wing in Tractor Configuration at Low-Reynolds-Number Condition Peer-reviewed

Masaki Okawa, Ren Nishimura, Tsubasa Ikami, Hiroki Nagai

Journal of Aircraft　2025/01

DOI： 10.2514/1.C037736 　
Three-dimensional density measurement around a Hayabusa re-entry capsule model in the ballistic range Peer-reviewed

Masato Yamagishi, Masanori Ota, Kiyonobu Ohtani, Hiroki Nagai

Experiments in Fluids　66　(1)　2024/12/27
Publisher: Springer Science and Business Media LLC
DOI： 10.1007/s00348-024-03943-5 　

ISSN： 0723-4864

eISSN： 1432-1114

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Abstract Three-dimensional density measurement around a Hayabusa re-entry capsule model using the background-oriented schlieren (BOS) technique is carried out in the ballistic range at the Institute of Fluid Science, Tohoku University. A Hayabusa re-entry capsule model with a diameter of 15 mm is used for a projectile, and the Mach number was 1.20. A method of model Position and Pose detection from BOS images was proposed for a capsule model, and unsteady flow field measurement around a free-flight test model was conducted. From the results, we succeeded in measuring the three-dimensional density distribution around a capsule model and visualizing the detailed structure in the wake region.
Spatiotemporal feature extraction using frequency-domain approach for flow-field data analysis Peer-reviewed

Tsubasa Ikami, Masaki Okawa, Makoto Takagi, Yasuhiro Egami, Yu Matsuda, Hiroki Nagai

Physics of Fluids　2024/12/01

DOI： 10.1063/5.0233760 　
Piezoelectric flutter energy harvesting: absolute nodal coordinate formulation model and wind tunnel experiment Peer-reviewed

Taisei Mukogawa, Kento Shimura, Shuonan Dong, Koji Fujita, Hiroki Nagai, Masaki Kameyama, Yu Shi, Yu Jia, Constantinos Soutis, Hiroki Kurita, Fumio Narita, Yushin Hara, Kanjuro Makihara, Keisuke Otsuka

Mechanics Research Communications　104351-104351　2024/11
Publisher: Elsevier BV
DOI： 10.1016/j.mechrescom.2024.104351 　

ISSN： 0093-6413
Effect of filling pressure on operating characteristics of a gravity-assisted nitrogen cryogenic loop heat pipe Peer-reviewed

Takeshi Yokouchi, Xinyu Chang, Kimihide Odagiri, Hiroyuki Ogawa, Hosei Nagano, Hiroki Nagai

International Journal of Heat and Mass Transfer　231　2024/10

DOI： 10.1016/j.ijheatmasstransfer.2024.125805 　

ISSN： 0017-9310
Dynamic instability in lift-type reentry capsule at supersonic flow Peer-reviewed

Yasuhito Okano, Shintaro Sato, Hiroki Nagai, Naofumi Ohnishi

Physics of Fluids　36　(7)　2024/07/01
Publisher: AIP Publishing
DOI： 10.1063/5.0217605 　

ISSN： 1070-6631

eISSN： 1089-7666

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Numerical simulations were conducted to investigate dynamic instability of a Japanese lift-type reentry capsule, which is named H-II transfer vehicle Recovery Vehicle (HRV), at Mach 1.2 by comparing two capsule shapes of an original HRV model and a model with a different shoulder angle of 10°. The 10° model has a thicker aft-body with a smaller shoulder angle than the original model. A previous pitch-direction One-Degree Of Freedom (1DOF) experiment revealed that the original model was dynamically stable, whereas the 10° model was dynamically unstable at Mach 1.2. So as to reproduce the same trends as the experiment, a high-order numerical scheme and zonal detached eddy simulation were employed. In fixed angle simulations, we found that the static longitudinal stability of the 10° model is higher than that of the original model in contrast with the observed dynamic stability. 1DOF free oscillation simulations successfully reproduced the same trends as the experiment. We elucidated that the main factor of the dynamic instability of the HRV-type capsule is a hysteresis of a boundary layer separation on the upper side of the capsule. The hysteresis is induced by a variation of momentum in a boundary layer due to capsule motion. We also found that for HRV-type capsules, the lower the static stability within the statically stable range, the higher the dynamic stability might be. In addition, on the lower side, a sign of the work exerted by surrounding flow is different between the original model and the 10° model. A dynamic mode decomposition analysis indicated that the vortex structures on the capsule wake might induce this difference.
Triple decomposition and sparse representation for noisy pressure-sensitive paint data Peer-reviewed

Koyo Kubota, Makoto Takagi, Tsubasa Ikami, Yasuhiro Egami, Hiroki Nagai, Takahiro Kashikawa, Koichi Kimura, Yu Matsuda

Physics of Fluids　36　(7)　2024/07/01
Publisher: AIP Publishing
DOI： 10.1063/5.0220866 　

ISSN： 1070-6631

eISSN： 1089-7666

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Triple decomposition is a powerful analytical method for a deep understanding of the flow structure by extracting the mean value, organized coherent motion, and stochastic part from a fluctuating quantity. Here, we perform the triple decomposition of the spatial two-dimensional data, especially pressure-sensitive paint (PSP) data, since the PSP method is widely used to measure the pressure distribution on a surface in wind tunnel testing. However, the PSP data measuring near atmospheric pressure contain significant noise, and this makes it difficult to conduct the decomposition. To construct phase-averaged data representing an organized coherent motion, we propose a relatively simple method based on a multi-dimensional scaling plot of the cosine similarity between each PSP datum. Then, the stochastic part is extracted by selecting phase-averaged data with an appropriate phase angle based on the similarity between the measurement and phase-averaged data, and the PSP data are successfully decomposed. Moreover, we consider sparse optimal sensor positions, in which the data are effectively represented, based on the stochastic part as a data-driven approach. The optimal sensor positions are determined as a combinatorial optimization problem and estimated using Fujitsu computing as a service digital annealer. We reconstruct the pressure distribution from the pressure data at the optimal sensor positions using the mean value, organized coherent motion, and stochastic part obtained from the triple decomposition. The root mean square error between the pressure measured by a pressure transducer and the reconstructed pressure obtained by the proposed method is small, even when the number of modes and sensor points is small. The application of PSP measurement is expected to expand further, and the framework for calculating triple decomposition and sparse representation based on the decomposition will be useful for detailed flow analysis.
Comparison of the thermofluidic behaviors of 2-m nitrogen-charged cryogenic loop heat pipe under anti-gravity and horizontal conditions Peer-reviewed

Kimihide Odagiri, Xinyu Chang, Hiroki Nagai, Hiroyuki Ogawa

Applied Thermal Engineering　123878-123878　2024/07
Publisher: Elsevier BV
DOI： 10.1016/j.applthermaleng.2024.123878 　

ISSN： 1359-4311
Design optimization and experimental demonstration of a gravity-assisted cryogenic loop heat pipe

Xinyu Chang, Takeshi Yokouchi, Kimihide Odagiri, Hiroyuki Ogawa, Hosei Nagano, Hiroki Nagai

International Journal of Heat and Mass Transfer　221　125037-125037　2024/04

DOI： 10.1016/j.ijheatmasstransfer.2023.125037 　

ISSN： 0017-9310
Visualization of thermo-fluid behavior of loop heat pipe with two evaporators and one condenser under various orientations with uneven heat loads

Xinyu Chang, Noriyuki Watanabe, Hiroki Nagai, Hosei Nagano

International Journal of Heat and Mass Transfer　221　125054-125054　2024/04

DOI： 10.1016/j.ijheatmasstransfer.2023.125054 　

ISSN： 0017-9310
Overview and Quick Report of Free Flight Test of Hayabusa-Type Larger Sample Return Capsule using Scientific Balloon in Australia Peer-reviewed

JAXA-RR-23-003　77-104　2024/02

DOI： 10.20637/0002000250 　
Numerical investigation on necessary condition for temperature oscillation in loop heat pipe Peer-reviewed

Takuya Adachi, Xinyu Chang, Hiroki Nagai, Shun Takahashi

International Journal of Thermal Sciences　196　108704-108704　2024/02
Publisher: Elsevier BV
DOI： 10.1016/j.ijthermalsci.2023.108704 　

ISSN： 1290-0729
cntTSP visualization technique for rotating blade surface flow at low Reynolds number

Tsubasa Ikami, Ren Nishimura, Hiroki Nagai

Experiments in Fluids　65　(2)　2024/01/18

DOI： 10.1007/s00348-023-03757-x 　

ISSN： 0723-4864

eISSN： 1432-1114
Clustering method for time-series images using quantum-inspired digital annealer technology Peer-reviewed

Tomoki Inoue, Koyo Kubota, Tsubasa Ikami, Yasuhiro Egami, Hiroki Nagai, Takahiro Kashikawa, Koichi Kimura, Yu Matsuda

Communications Engineering　2024/01/10

DOI： 10.1038/s44172-023-00158-0 　
Numerical Study on Unsteady Flow Field Structure over Wing within Propeller Slipstream at Low-Reynolds-Number Peer-reviewed

Yoshikatsu FURUSAWA, Keiichi KITAMURA, Tsubasa IKAMI, Hiroki NAGAI

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN　22　49-58　2024
Publisher: Japan Society for Aeronautical and Space Sciences
DOI： 10.2322/tastj.22.49 　

eISSN： 1884-0485
Numerical Study on Aerodynamic Characteristics of Wing within Propeller Slipstream at Low-Reynolds-Number Peer-reviewed

Yoshikatsu FURUSAWA, Keiichi KITAMURA, Tsubasa IKAMI, Hiroki NAGAI, Akira OYAMA

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES　67　(1)　12-22　2024
Publisher: Japan Society for Aeronautical and Space Sciences
DOI： 10.2322/tjsass.67.12 　

ISSN： 0549-3811

eISSN： 2189-4205
Numerical Investigation of the Dynamic Instability of a Reentry Capsule in Transonic Flow Peer-reviewed

Seoeum Han, Bok Jik Lee, Michiko Ahn Furudate, Hiroki Nagai

AIAA Journal　1-11　2023/11/07
Publisher: American Institute of Aeronautics and Astronautics (AIAA)
DOI： 10.2514/1.j063428 　

ISSN： 0001-1452

eISSN： 1533-385X

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This study presents a numerical investigation of transonic flow characteristics over a reentry capsule at Mach 1.05, employing a detached eddy simulation. The simulated flowfields demonstrate that the recompression shock wave oscillates back and forth at a Strouhal number of the order of 0.01. Frequency analysis of fluctuations in the drag coefficient and base pressure reveals that these fluctuations can be predominantly attributed to oscillations in the recompression shock wave. While the recompression shock wave propagates upstream, local shock waves occur alternately in the upper and lower free-shear layers, with a Strouhal number of the order 0.1, due to the instability of free-shear layers. The repeated occurrence of these local shock waves causes the recirculation region to shrink, resulting in a decrease in the base pressure. Conversely, while the recompression shock wave propagates downstream, no local shock wave occurs and the recirculation region expands, leading to an increase in the base pressure. These results suggest that the interactions among the recompression shock wave, local shock wave, and free shear layer give rise to fluctuations in the base pressure of the capsule, which in turn can affect its dynamic instability.
Thermal surrogate model for spacecraft systems using physics-informed machine learning with POD data reduction Peer-reviewed

Hiroto Tanaka, Hiroki Nagai

International Journal of Heat and Mass Transfer　213　124336-124336　2023/10
Publisher: Elsevier BV
DOI： 10.1016/j.ijheatmasstransfer.2023.124336 　

ISSN： 0017-9310
On the energy harvesting technique using a fluttering PVDF film with flow-induced vibration Peer-reviewed

Naoyuki TAKEDA, Koki SHIGE, Osamu TERASHIMA, Tsubasa IKAMI, Hiroki NAGAI, Yasufumi KONISHI, Toshihiko KOMATSUZAKI

Advanced Experimental Mechanics　8　25-31　2023/08

DOI： 10.11395/aem.8.0_25 　
Data-driven thermal state estimation for in-orbit systems via physics-informed machine learning Peer-reviewed

Hiroto Tanaka, Hiroki Nagai

Acta Astronautica　212　316-328　2023/08
Publisher: Elsevier BV
DOI： 10.1016/j.actaastro.2023.07.039 　

ISSN： 0094-5765
Effect of Flow Resistance of Floating-Type Check Valves on Heat Transfer Characteristics of an Oscillating Heat Pipe Peer-reviewed

Makiko Ando, Atsushi Okamoto, Hiroki Nagai

ASME Journal of Heat and Mass Transfer　145　(10)　2023/07/17
Publisher: ASME International
DOI： 10.1115/1.4062783 　

ISSN： 2832-8450

eISSN： 2832-8469

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Abstract An oscillating heat pipe with check valves (CVOHP) is an attractive heat transfer device for future spacecraft with considerable heat dissipation and ground applications. This study aims to clarify the effect of the flow resistance of floating-type check valves on the heat transfer characteristics of the CVOHP using a one-dimensional slug flow model, which simulates the five-turn CVOHP used in the on-orbit experiment by the authors. The numerical simulations were conducted for different flow resistances, positions, and numbers of check valves. The results showed that the thermal resistance of the CVOHP increases with the flow resistance of the check valves, while there is no significant effect on the startup characteristics. The thermal resistance increased by more than 100% in the worst case, and the recommended flow resistance coefficient of the check valve was below 100 in this study for high thermal performance. The thermal resistance increases with an increasing number of high-resistance check valves but is less affected by the position of the valve. Additionally, the higher the heat input, the greater the effect of the flow resistance of the check valves. According to the findings in this study, it is necessary to control the flow resistance of the floating-type check valves at a low level for the high thermal performance of a CVOHP.
Effect of heat load to a capillary starter pump on the thermal characteristics of a 2-m nitrogen cryogenic loop heat pipe

Kimihide Odagiri, Xinyu Chang, Hiroki Nagai, Hiroyuki Ogawa

Applied Thermal Engineering　121109-121109　2023/07
Publisher: Elsevier BV
DOI： 10.1016/j.applthermaleng.2023.121109 　

ISSN： 1359-4311
Evaluation of the frequency characteristics of cntTSP measurement for unsteady low-speed flow Peer-reviewed

Tsubasa Ikami, Yasufumi Konishi, Hiroki Nagai

Measurement Science and Technology　34　(6)　065301-065301　2023/02/03
Publisher: IOP Publishing
DOI： 10.1088/1361-6501/acb8d0 　

ISSN： 0957-0233

eISSN： 1361-6501

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Abstract cntTSP is a fluid measurement technology that utilizes temperature-sensitive paint (TSP). It works as an optical temperature sensor, with a thin layer of carbon nanotubes (CNT) to heat the TSP layer. This study investigated the frequency characteristics of cntTSP measurements in low-speed flow. The flow field on the flat plate was periodically changed by introducing intermittent local disturbances to the flat plate in a low-speed wind tunnel test. cntTSP measurement was conducted behind the local disturbance to evaluate changes in the temperature associated with periodic changes in the flow. The amplitude of the temperature change decreased approximately linearly with the frequency in a double-logarithmic graph. Moreover, the temperature amplitude at 25 Hz was 0.0082 K, and it was necessary to detect a very small temperature change to evaluate high-frequency phenomena.
Comparison of heat-transfer performance of a flat-plate pulsating heat pipe based on heating orientation and cross-sectional shape of the pipe

Yosuke YASUDA, Fumika NABESHIMA, Keisuke HORIUCHI, Hiroki NAGAI

Mechanical Engineering Journal　2023/02
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/mej.22-00415 　

eISSN： 2187-9745
Joint parameters for strain-based geometrically nonlinear beam formulation: Multibody analysis and experiment

Keisuke Otsuka, Shuonan Dong, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

Journal of Sound and Vibration　538　117241-117241　2022/11

DOI： 10.1016/j.jsv.2022.117241 　

ISSN： 0022-460X
Numerical analysis of loop heat pipe using nucleate boiling model in evaporator core

Takuya Adachi, Xinyu Chang, Hiroki Nagai

International Journal of Heat and Mass Transfer　195　123207-123207　2022/10
Publisher: Elsevier BV
DOI： 10.1016/j.ijheatmasstransfer.2022.123207 　

ISSN： 0017-9310
Consistent Strain-Based Multifidelity Modeling for Geometrically Nonlinear Beam Structures International-journal International-coauthorship Peer-reviewed

Otsuka, K, Wang, Y, Fujita, K, Nagai, H, Makihara, K

Transactions of ASME, Journal of Computational and Nonlinear Dynamics　17　(11)　111003　2022/09
Publisher: ASME International
DOI： 10.1115/1.4055310 　

ISSN： 1555-1415

eISSN： 1555-1423

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Abstract Conventional multifidelity modeling for slender structures such as folding-wing aircraft and offshore wind turbines does not allow the generation of multiple fidelity models that consistently use the same external force model, which complicates simulation program and design process. Although consistent absolute nodal coordinate formulation (ANCF)-based multifidelity modeling was recently proposed to address this inconsistency, it still has the following four problems: (1) a large number of generalized coordinates, (2) a large number of Lagrange multipliers, (3) difficulty in constraining high-frequency axial deformation, and (4) a lack of lower-fidelity models. The lower-fidelity models that have not yet been developed are torsion-only beam, extension-only truss, and bending-only beam models. The objective of this study was to develop a novel consistent strain-based multifidelity modeling framework that addresses these problems by leveraging new vector–strain transformations from ANCF to the strain-based beam formulation. We employed a hydrodynamic force model based on Morison's equation as an example to demonstrate all fidelity models obtained from the proposed strain-based framework consistently use the same external force model. We conducted five simulations to verify the proposed models. The consistent external force model for the hydrodynamic force was then validated by comparison with experimental data. The simulation results concurred with those of conventional models and experiments. Low-fidelity models exhibited over 98% reduction in calculation time compared to high-fidelity models, which helps in conceptual and initial designs that require a large number of parametric simulations.
UNSTEADY PRESSURE DISTRIBUTION MEASUREMENT ON CYLINDER SURFACE USING ANODIZED ALUMINUM PRESSURE-SENSITIVE PAINT DURING SHOCK WAVE PASSAGE Peer-reviewed

S. Tamakuma, K. Yomo, T. Ogawa, H. Nagai

Proceedinggs of The 13th Pacific Symposium on Flow Visualization and Image Processing　2022/08
Thermal Vacuum Testing of Advanced Thermal Control Devices for Flight Demonstration Peer-reviewed

Satoshi Kajiyiama, Takuji Mizutani, Takuya Ishizaki, Kota Tomioka, Hosei Nagano, Hiroto Tanaka, Hiroki Nagai, Kan Matsumoto, Kenichiro Sawada, Yoshihiro Machida, Kazuaki Matsumoto

Proceedings of 51th International Conference on Environmental Systems　2022/07
Evaluation of temperature estimation accuracy using Physics-Informed Neural Network for small satellite model Peer-reviewed

Hiroto Tanaka, Koji Fujita, Hiroki Nagai

Proceedings of 51th International Conference on Environmental Systems　2022/07
Investigation of Formulations on Pyrene-Based Anodized-Aluminum Pressure-Sensitive Paints for Supersonic Phenomena Peer-reviewed

Hiroki Nagai

Sensors　22　(12)　4430-4430　2022/06/11

DOI： 10.3390/S22124430 　

eISSN： 1424-8220
Structured light illumination for pressure-sensitive paint measurement under ambient light International-journal Peer-reviewed

Yu Matsuda, Satoshi Katayama, Tsubasa Ikami, Yasuhiro Egami, Hiroki Nagai

Review of Scientific Instruments　93　(5)　055101-055101　2022/05/01
Publisher: AIP Publishing
DOI： 10.1063/5.0089000 　

ISSN： 0034-6748

eISSN： 1089-7623

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We propose a pressure-sensitive paint (PSP) method under ambient light based on structured light illumination. In the PSP method, pressure is obtained by measuring the variation of the emission light intensity from a PSP coating when it is illuminated by a light source. Since the extraction of the emission light from ambient light is difficult in the conventional PSP method, the existence of ambient light induces a noticeable measurement error. While spatially uniform light is used as illumination light in the conventional PSP method, structured light, the spatial intensity of which is actively controlled, is used in the proposed method. By measuring the PSP emission by varying the spatial pattern of the structured light illumination, one can eliminate ambient light, which is not synchronized with the structured light and can measure pressure without the effect of ambient light. In this study, we demonstrate the pressure measurement under ambient light using structured light with a sinusoidal wave generated by a digital mirror device. The measured pressure agrees well with the pressure measured by a pressure transducer connected to a pressure tap. The proposed method is promising under ambient light conditions.
Visualization of the working fluid in a flat-plate pulsating heat pipe by neutron radiography Peer-reviewed

Hiroki Nagai

International Journal of Heat and Mass Transfer　185　122336-122336　2022/04

DOI： 10.1016/J.IJHEATMASSTRANSFER.2021.122336 　

ISSN： 0017-9310
Numerical Analysis of Wick-Type Two-Phase Mechanically Pumped Fluid Loop for Thermal Control of Electric Aircraft Motors Peer-reviewed

Hiroki Nagai

Energies　15　(5)　1800-1800　2022/02/28

DOI： 10.3390/EN15051800 　

eISSN： 1996-1073
Influence of Formulations on Characteristics of Ruthenium-Based Temperature-Sensitive Paints Peer-reviewed

Hiroki Nagai

Sensors　22　(3)　901-901　2022/01/25

DOI： 10.3390/S22030901 　

eISSN： 1424-8220
Noise Reduction in PSP Images Using Mathematical Optimization Method Peer-reviewed

Tomoki INOUE, Yu MATSUDA, Tsubasa IKAMI, Taku NONOMURA, Yasuhiro EGAMI, Hiroki NAGAI

Journal of the Japan Society for Precision Engineering　87　(7)　7_610-7_613　2021/07/05
Publisher: Japan Society for Precision Engineering
DOI： 10.2493/jjspe.87.7_610 　

ISSN： 0912-0289

eISSN： 1882-675X
Data-driven approach for noise reduction in pressure-sensitive paint data based on modal expansion and time-series data at optimally placed points Peer-reviewed

Tomoki Inoue, Yu Matsuda, Tsubasa Ikami, Taku Nonomura, Yasuhiro Egami, Hiroki Nagai

Physics of Fluids　33　(7)　077105-077105　2021/07
Publisher: AIP Publishing
DOI： 10.1063/5.0049071 　

ISSN： 1070-6631

eISSN： 1089-7666
Measurement of boundary layer transition on oscillating airfoil using cntTSP in low-speed wind tunnel Peer-reviewed

Tsubasa Ikami, Koji Fujita, Hiroki Nagai, Daisuke Yorita

Measurement Science and Technology　32　(7)　075301-075301　2021/07/01
Publisher: IOP Publishing
DOI： 10.1088/1361-6501/abe2be 　

ISSN： 0957-0233

eISSN： 1361-6501

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Abstract cntTSP is a flow visualization technique that combines temperature-sensitive paint (TSP) and carbon nanotube (CNT). TSP is a sprayable temperature sensor, and CNT is used as a thin inner electric heater for the TSP. The cntTSP technique allows the visualization of the movement of the boundary layer transition on a moving airfoil. In this study, cntTSP was applied to a pitch-oscillating airfoil in a low-speed wind tunnel. Three methods were compared as methods for detecting the boundary layer transition position. The transition position was successfully evaluated using a heat transfer coefficient that was calculated by the surface temperature. Moreover, at a high-reduced frequency, the detected transition positions were different between the pitching-up and pitching-down procedure. Moreover, we observed a hysteresis loop of the transition position.
Start-up and heat transfer characteristics of oscillating heat pipe with different check valve layouts Peer-reviewed

Hiroki Nagai

Applied Thermal Engineering　117286-117286　2021/06

DOI： 10.1016/J.APPLTHERMALENG.2021.117286 　

ISSN： 1359-4311
Aeroelastic deformation measurement of Martian airplane for high-altitude flight experiment using stereophotogrammetry Peer-reviewed

Shuichi Hiramatsu, Masayuki Anyoji, Koji Fujita, Hiroki Nagai, Akira Oyama, Hiroyuki Kato

Engineering Research Express　3　(1)　015035-015035　2021/03/01
Publisher: IOP Publishing
DOI： 10.1088/2631-8695/abe920 　

eISSN： 2631-8695

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<title>Abstract</title> A fixed-wing aircraft called Mars Airplane Balloon Experiment −2 (MABE2) developed by the authors was the subject of high-altitude flight demonstration test in this paper, which can simulate the near-actual environment of a Martian atmospheric flight. Although the flight condition is in the low-Reynolds-number region due to low density at high altitude, the wing suffers from aeroelastic deformation given the relatively high dynamic pressure load in the pull-up phase. Stereophotogrammetry was applied in the 6.5 m × 5.5 m low-speed wind tunnel at the Japan Aerospace Exploration Agency (JAXA), aiming to optically measure MABE2’s aeroelastic deformation under dynamic pressure loads equivalent to high-altitude flight test, with the MABE2’s reinforced structural strength. The results of the accuracy test indicated that stereophotogrammetry measures aeroelastic deformation at high accuracy of ±0.1 mm around the image center and ±0.3 mm around the edge. A slight deflection of up to 4 mm was observed on the main wing, whereas both the main and tail wings were hardly twisted. Compared with flight-simulation-assumed errors, these deformations are extremely small and have a negligible effect on the high-altitude flight test. The study results confirmed the practicality and efficiency of this optical measurement technique in aeroelastic deformation measurement for a real light aircraft.
Ruthenium-based fast-responding pressure-sensitive paint for measuring small pressure fluctuation in low-speed flow field

Y Egami, Y Hasegawa, A Matsuda, T Ikami, H Nagai

Measurement Science and Technology　32　(2)　024003-024003　2021/02/01
Publisher: IOP Publishing
DOI： 10.1088/1361-6501/abb916 　

ISSN： 0957-0233

eISSN： 1361-6501
Quantitative density measurement of wake region behind reentry capsule (Improvements in accuracy of 3D reconstruction by evaluating the view-angle of measurement system)

Masato YAMAGISHI, Yusuke YAHAGI, Masanori OTA, Yusuke HIROSE, Shinsuke UDAGAWA, Tatsuro INAGE, Shigeya KUBOTA, Koji FUJITA, Kiyonobu OHTANI, Hiroki NAGAI

Journal of Fluid Science and Technology　16　(3)　JFST0021-JFST0021　2021
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/jfst.2021jfst0021 　

eISSN： 1880-5558
Accuracy Evaluation Method of Inertial Measurement Unit Using Optical Motion Capture System Peer-reviewed

Koji Fujita, Daisuke Kubo, Akira Oyama, Hiroki Nagai

AEROSPACE TECHNOLOGY JAPAN, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES　20　101-104　2021
Publisher: Japan Society for Aeronautical and Space Sciences
DOI： 10.2322/astj.20.101 　

eISSN： 1884-0477
Investigation of Data Acquisition Conditions for Dynamic Mode Decomposition in Unsteady PSP Measurement Peer-reviewed

Tsubasa IKAMI, Koji FUJITA, Hiroki NAGAI, Yu MATSUDA, Yasuhiro EGAMI

Transactions of the Visualization Society of Japan　41　(6)　11-20　2021
Publisher: The Visualization Society of Japan
DOI： 10.3154/tvsj.41.11 　

ISSN： 2433-2275

eISSN： 1346-5260
Thermal state estimation based on Assisted Ensemble Kalman Filter Peer-reviewed

Hiroto TANAKA, Takashi MISAKA, Koji FUJITA, Hiroki NAGAI

Transactions of the JSME (in Japanese)　87　(898)　21-00010　2021
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/transjsme.21-00010 　

eISSN： 2187-9761
Supersonic Ejector-Driving System under Low Pressure: A Performance Evaluation Peer-reviewed

Hiroki Nagai

Transactions of the Japan Society for Aeronautical and Space Sciences　64　(3)　156-164　2021

DOI： 10.2322/TJSASS.64.156 　

ISSN： 0549-3811

eISSN： 2189-4205
Conceptual Design of Micro Mars Airplane Using Inflatable Wing

Issei Mamiya, Koji Fujita, Hiroki Nagai

JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES　69　(1)　16-23　2021
Publisher: Japan Society for Aeronautical and Space Sciences
DOI： 10.2322/jjsass.69.16 　

ISSN： 1344-6460

eISSN： 2432-3691
Effects of Propeller Position and Rotation Direction on the Ishii Wing at a Low Reynolds Number

Hiroki Nagai

Transactions of the Japan Society for Aeronautical and Space Sciences　64　(1)　22-30　2021

DOI： 10.2322/TJSASS.64.22 　

ISSN： 0549-3811

eISSN： 2189-4205
Low-Reynolds-Number Flowfield of Wing with Control Surface in Propeller Slipstream Peer-reviewed

Hiroki Nagai

Journal of Aircraft　58　(2)　228-235　2021

DOI： 10.2514/1.C035880 　

eISSN： 1533-3868
Sub-millimeter resolution pressure measurement on free flight model at Mach 1.5 using novel non-intrusive optical technique

Hiroki Nagai

Experimental Thermal and Fluid Science　120　110243-110243　2021/01

DOI： 10.1016/J.EXPTHERMFLUSCI.2020.110243 　

ISSN： 0894-1777
Application of pressure-sensitive paint for the characterization of mixing with various gases in T-type micromixers

Hiroki Nagai

International Journal of Heat and Mass Transfer　156　119710-119710　2020/08

DOI： 10.1016/J.IJHEATMASSTRANSFER.2020.119710 　

ISSN： 0017-9310
A Feasibility Analysis of Collaborative Mission Using Mars Airplane and Mars Balloon - Mars Aerial-Exploration for Terrestrial and Tropospheric Environment Observation -

Hiroto TANAKA, Issei MAMIYA, Hideki KIRITANI, Hiroki NAGASAWA, Takumi HIRATA, Tatsuya TONAI, Hiroki NAGAI, Koji FUJITA

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN　18　(3)　64-70　2020
Publisher: Japan Society for Aeronautical and Space Sciences
DOI： 10.2322/tastj.18.64 　

eISSN： 1884-0485
Heat transfer performance of Pulsating Heat Pipe with Hydrofluoroolefin Peer-reviewed

Yosuke YASUDA, Fumika NABESHIMA, Sunao FUNAKOSHI, Hiroki NAGAI

Transactions of the JSME (in Japanese)　86　(890)　20-00127　2020
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/transjsme.20-00127 　

eISSN： 2187-9761
Attitude Estimation using Thermopile Sensors on Mars Airplane Balloon Experiment-1 (MABE-1) Peer-reviewed

TOKUTAKE Hiroshi, FUJITA Koji, OYAMA Akira, NAGAI Hiroki

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN　18　(2)　17-24　2020
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/tastj.18.17 　

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In this study,an attitude estimation method for a Mars airplane is proposed.Infrared radiation from the atmosphere and the ground and visible light radiation from the sun were modeled as functions of attitude.The radiation models were provided to an attitude estimation algorithm,where the Euler angles and the uncertain parameters of the radiation model were optimized such that the error between the radiation sensor output and radiation model output is minimized.The method proposed was validated using the data acquired during high-altitude flight experiment on Earth,which was simulating flight on Mars.The estimated results were compared with the integration of the angular velocity sensor output,and the precision was evaluated and discussed.
Numerical study of temperature oscillation in loop heat pipe Peer-reviewed

Takuya Adachi, Koji Fujita, Hiroki Nagai

Applied Thermal Engineering　163　2019/12/25

DOI： 10.1016/j.applthermaleng.2019.114281 　

ISSN： 1359-4311
Aerodynamic performance of control surfaces on mars airplane balloon experiment two Peer-reviewed

Masahiro Kanazaki, Kai Tomisawa, Koji Fujita, Akira Oyama, Hiroki Nagai

Journal of Fluid Science and Technology　14　(3)　JFST0017-JFST0017　2019/12/19
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jfst.2019jfst0017 　

eISSN： 1880-5558
The Quantitative Density Measurement of Unsteady Flow around the Projectile Peer-reviewed

Yusuke Hirose, Kazuki Ishikawa, Yoshiyuki Ishimoto, Takumi Nagashima, Masanori Ota, Shinsuke Udagawa, Tatsuro Inage, Kazuki Fujita, Hideki Kiritani, Koji Fujita, Kiyonobu Ohtani, Hiroki Nagai

Journal of Flow Control, Measurement & Visualization　111-119　2019/07
Publisher: Scientific Research Publishing Inc.
DOI： 10.4236/jfcmv.2019.72009 　
Wind Tunnel Test for Videogrammetric Deformation Measurement of UAV for Mars Airplane Balloon Experiment-1 (MABE-1)* Peer-reviewed

Koji Fujita, Akira Oyama, Daisuke Kubo, Masahiro Kanazaki, Hiroki Nagai

Journal of Flow Control, Measurement & Visualization　(7)　87-100　2019/04/04
Publisher: Scientific Research Publishing Inc.
ISSN： 2329-3322
Multifidelity modeling of deployable wings: Multibody dynamic simulation and wind tunnel experiment Peer-reviewed

Keisuke Otsuka, Yinan Wang, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

AIAA Journal　57　(10)　4300-4311　2019

DOI： 10.2514/1.J058676 　

ISSN： 0001-1452
Flight Control Parameter Design for Mars Airplane Balloon Experiment-1 (MABE-1) Using Evolutionary Computation Peer-reviewed

FUJITA Koji, TOKUTAKE Hiroshi, NAGAI Hiroki, OYAMA Akira

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN　17　(4)　512-518　2019
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/tastj.17.512 　

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Airplanes are paid attention as a new platform for Mars exploration. A high-altitude flight test using balloon was conducted in June 2016 by Japanese working group for Mars exploration aircraft. This paper reports a method of control gain tuning for the flight test using evolutionary computation approach. This method can find optimal robust control gains efficiently and automatically. The combination of the control gains are evaluated by the simulations of a finite number of the dispersion conditions defined by the sensitivity analysis. A summary of a flight test, a control law, an optimization method, a flight simulation method, an evaluation function setting, and an optimization result are described.
Aerodynamic Challenge for Realization of Mars Airplane Peer-reviewed

NAGAI Hiroki, OYAMA Akira, ANYOJI Masayuki, OKAMOTO Masato, FUJITA Koji, YONEMOTO Koichi

Aeronautical and Space Sciences Japan　67　(6)　215-222　2019
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.14822/kjsass.67.6_215 　

ISSN： 0021-4663
On-orbit demonstration of oscillating heat pipe with check valves for space application Peer-reviewed

Makiko Ando, Atsushi Okamoto, Kosuke Tanaka, Masakatsu Maeda, Hiroyuki Sugita, Takurou Daimaru, Hiroki Nagai

Applied Thermal Engineering　130　552-560　2018/02/05

DOI： 10.1016/j.applthermaleng.2017.11.032 　

ISSN： 1359-4311
Computational study of aerodynamic characteristics on reentry capsule aft-body shape in transonic flow

Masayuki Nomura, Koji Fujita, Hiroki Nagai

AIAA Atmospheric Flight Mechanics Conference, 2018　(209999)　2018

DOI： 10.2514/6.2018-0290 　
Robustness analysis on aerial deployment motion of a Mars aircraft using multibody dynamics simulation: Effects of wing-unfolding torque and timing Peer-reviewed

Koji Fujita, Hiroki Nagai

Aeronautical Journal　121　(1238)　449-468　2017/04

DOI： 10.1017/aer.2016.123 　

ISSN： 0001-9240
Study on thermal cycle in oscillating heat pipes by numerical analysis Peer-reviewed

Takurou Daimaru, Shuhei Yoshida, Hiroki Nagai

Applied Thermal Engineering　113　1219-1227　2017/02

DOI： 10.1016/j.applthermaleng.2016.11.114 　

ISSN： 1359-4311
Evaluation of Aerodynamic Performance of Mars Airplane in Scientific Balloon Experiment Peer-reviewed

Masayuki Anyoji, Masato Okamoto, Koji Fujita, Hiroki Nagai, Akira Oyama

Fluid Mechanics Research International Journal　1　(3)　2017

DOI： 10.15406/fmrij.2017.01.00012 　
Ultrafast-response anodized-Aluminum pressure-sensitive paints for unsteady flow measurement Peer-reviewed

Daiju Numata, Shota Fujii, Hiroki Nagai, Keisuke Asai

AIAA Journal　55　(4)　1118-1125　2017

DOI： 10.2514/1.J054886 　

ISSN： 0001-1452
Characterization of frequency response of pressure-sensitive paints Peer-reviewed

Tamao Sugimoto, Yosuke Sugioka, Daiju Numata, Hiroki Nagai, Keisuke Asai

AIAA Journal　55　(4)　1460-1464　2017

DOI： 10.2514/1.J054985 　

ISSN： 0001-1452
Comparison between numerical simulation and on-orbit experiment of oscillating heat pipes Peer-reviewed

Takurou Daimaru, Hiroki Nagai, Makiko Ando, Kosuke Tanaka, Atsushi Okamoto, Hiroyuki Sugita

International Journal of Heat and Mass Transfer　109　791-806　2017

DOI： 10.1016/j.ijheatmasstransfer.2017.01.078 　

ISSN： 0017-9310
Effects of Ge substitution on thermoelectric properties of CrSi2

Hiroki Nagai

Japanese Journal of Applied Physics　2016

DOI： 10.7567/JJAP.55.111801 　
Effects of Nb substitution on thermoelectric properties of CrSi2

Hiroki Nagai

Journal of Alloys and Compounds　2016

DOI： 10.1016/J.JALLCOM.2016.06.047 　
Development of a Cooling System for GAPS using Oscillating Heat Pipe

Hideyuki FUKE, Takumi ABE, Takuro DAIMARU, Takayoshi INOUE, Akiko KAWACHI, Hiroki KAWAI, Yosuke MASUYAMA, Hiroaki MATSUMIYA, Daishi MATSUMOTO, Yoshiro MIYAZAKI, Junichi MORI, Hiroki NAGAI, Taku NONOMURA, Hiroyuki OGAWA, Shun OKAZAKI, Takuma OKUBO, Shinji OZAKI, Daisuke SATO, Kensei SHIMIZU, Katsumasa TAKAHASHI, Shun TAKAHASHI, Noboru YAMADA, Takanori YOSHIDA

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN　14　(ists30)　Pi_17-Pi_26　2016
Publisher: Japan Society for Aeronautical and Space Sciences
DOI： 10.2322/tastj.14.pi_17 　

eISSN： 1884-0485
Comparing Aerial-Deployment-Mechanism designs for mars airplane Peer-reviewed

Koji Fujita, Hiroki Nagai

Transactions of the Japan Society for Aeronautical and Space Sciences　59　(6)　323-331　2016

DOI： 10.2322/tjsass.59.323 　

ISSN： 0549-3811
Operational Characteristics of the Oscillating Heat Pipe with Noncondensable Gas Peer-reviewed

Hiroki Nagai

Journal of Thermophysics and Heat Transfer　29　(3)　563-571　2015/07

DOI： 10.2514/1.T4461 　

ISSN： 0887-8722

eISSN： 1533-6808
Pressure-sensitive paint technique for surface pressure measurements in a low-density wind tunnel Peer-reviewed

M. Anyoji, D. Numata, H. Nagai, K. Asai

Journal of Visualization　18　(2)　297-309　2015/05/01

DOI： 10.1007/s12650-014-0239-9 　

ISSN： 1343-8875

eISSN： 1875-8975
The applications of pressure-sensitive paint in microfluidic systems Peer-reviewed

Chih Yung Huang, Yu Matsuda, James W. Gregory, Hiroki Nagai, Keisuke Asai

Microfluidics and Nanofluidics　18　(5-6)　739-753　2015/05/01

DOI： 10.1007/s10404-014-1510-z 　

ISSN： 1613-4982

eISSN： 1613-4990
Study on internal flow characteristics of multiple evaporators loop heat pipe (Visualization in evaporators and condenser under microgravity) Peer-reviewed

MATSUDA Yuta, NAGANO Hosei, OKAZAKI Shun, OGAWA Hiroyuki, NAGAI Hiroki

Transactions of the JSME (in Japanese)　81　(827)　15-00104-15-00104　2015
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/transjsme.15-00104 　

ISSN： 2187-9761

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Loop Heat Pipes (LHPs) have been used in thermal control of spacecraft as next generation heat transport devices. Recently, multiple-evaporators LHP (MLHP) is under studied since the MLHP supplies autonomous thermal control function. However, some physical phenomena in the MLHP have not been clarified yet. The purpose of this study is to clarify thermal behavior of the MLHP under the microgravity. The MLHP used in this research has two evaporators and one condenser. Distilled water is used as the working fluid. 40W/40W, 80W/80W, 120W/0W, 0W/120W heat load were applied during the test. This experiment was conducted under microgravity for about 20 seconds, which was realized by parabolic flight. The vapor-liquid distribution in the wick core and the compensation chamber (CC) under the microgravity is presented. The effect of the microgravity for the working the MLHP is also discussed. The heat distributions in the MLHP when one and both evaporators were heated is also clarified
Effects of mach number and specific heat ratio on low-reynolds-number airfoil flows Peer-reviewed

Masayuki Anyoji, Daiju Numata, Hiroki Nagai, Keisuke Asai

AIAA Journal　53　(6)　1640-1654　2015

DOI： 10.2514/1.J053468 　

ISSN： 0001-1452
Computational and experimental analysis of a high-performance airfoil under low-reynolds-number flow condition Peer-reviewed

Masayuki Anyoji, Taku Nonomura, Hikaru Aono, Akira Oyama, Kozo Fujii, Hiroki Nagai, Keisuke Asai

Journal of Aircraft　51　(6)　1864-1872　2014/11/01

DOI： 10.2514/1.C032553 　

ISSN： 0021-8669

eISSN： 1533-3868
An Investigation of Airfoils for Development of a Propeller of Mars Exploration Airplane

YONEZAWA Koichi, GOTO Yudai, SUNADA Shigeru, HAYASHIDA Takashi, SUWA Tetsuya, SAKAI Nobuaki, NAGAI Hiroki, ASAI Keisuke, TSUJIMOTO Yoshinobu

JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES　62　(1)　24-30　2014
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/jjsass.62.24 　

ISSN： 1344-6460

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Aerodynamic performances of four kinds of airfoils are examined in flows with low-Reynolds number. The aim of the present study is to find the airfoil shape, which provides a large value of a maximum lift-drag ratio in order to develop a high efficiency propeller for the Mars exploration airplane. A triangle airfoil is a base contour of the test airfoils and effects of blunt trailing edges on airfoil characteristics are examined using numerical simulations. Furthermore, a variation of aerodynamic characteristics of one airfoil with a blunt trailing edge due to decreased thickness and increased camber is also examined. The numerical results are verified by experiments. As the trailing edge thickness is increased, the lift-drag ratio becomes larger and values of the lift and the drag forces become smaller at the angle of attack where the lift-drag ratio becomes maximum. By increasing the trailing edge thickness, the boundary layer separation is suppressed and the aerodynamic forces are reduced. The increased camber and decreased thickness yield a significant lift increase of the airfoil with the blunt trailing edge and a small amount of drag increase. As a result, the airfoil with the blunt trailing edge yields large value of the lift-drag ratio in the flows with low-Reynolds numbers.
Control surface effectiveness of low Reynolds number flight vehicles

ANYOJI Masayuki, OKAMOTO Masato, HIDAKA Hidenori, KONDO Katsutoshi, OYAMA Akira, NAGAI Hiroki, FUJII Kozo

Journal of Fluid Science and Technology　9　(5)　JFST0072-JFST0072　2014
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jfst.2014jfst0072 　

ISSN： 1880-5558

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Low-speed wind tunnel tests are carried out to investigate the control surface effectiveness at low Reynolds numbers (Re = 20,000-80,000). A thick airfoil, NACA0012, has a nonlinearity of the control surface effectiveness, which are associated with flow separation both on the upper and lower surfaces and a formation of a laminar separation bubble. Thin airfoils such as NACA0006 and a 3%c flat plate have a much smaller nonlinearity of the control surface effectiveness. These differences in the control surface effectiveness are due to the nonlinearity of the lift curve for each airfoil, and the flow separation behavior has a profound effect on the control surface effectiveness.
Operating characteristics of multiple evaporators and multiple condensers loop heat pipe with polytetrafluoroethylene wicks Peer-reviewed

Shou Okutani, Hosei Nagano, Shun Okazaki, Hiroyuki Ogawa, Hiroki Nagai

Journal of Electric Cooling and Thermal Control　4　(1)　22-32　2014
Non-Condensable Gas Effect in the Oscillating Heat Pipe Peer-reviewed

DAIMARU Takurou, NAGAI Hiroki

AEROSPACE TECHNOLOGY JAPAN, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES　13　(0)　17-24　2014
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/astj.13.17 　

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In this study, the effect of Non-Condensable Gas (NCG) in Oscillating Heat Pipe (OHP) was evaluated by using Closed Loop OHP (CLOHP) made of copper capillary tube. The working fluid was ethanol and the NCG was argon. Temperature and pressure were measured over the heat input range from 40 W to 180 W. The temperature amplitude, the thermal resistance, the pressure amplitude and frequency were calculated. From the results, the NCG affects the thermal performance of OHP.
Dynamic Behaviour of Mars Airplane with Folded-Wing Deployment

FUJITA Koji, MOTODA Toshikazu, NAGAI Hiroki

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN　12　(29)　Pk_1-Pk_6　2014
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/tastj.12.Pk_1 　

ISSN： 1884-0485

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An aerial deployment technique is required for the Mars airplane to get a large wing area and compactness. A multibody dynamics simulation program was developed to assess the safety of the dynamic behaviour during aerial deployment. An effect of an initial deployment angle was revealed through the simulation. A pitching moment was generated due to the drag and pitching moment acting on the right and left wings.
Propeller Slipstream Interference with Wing Aerodynamic Characteristics of Mars Airplane at Low Reynolds Number Peer-reviewed

MAKINO Fumiyasu, NAGAI Hiroki

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN　12　(29)　Tk_13-Tk_18　2014
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/tastj.12.Tk_13 　

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A flow condition on the wing of Mars airplane becomes low Reynolds number (10⁴ to 10⁵) for a reason of low atmospheric density on the Mars. However an effect of a propeller slipstream for the wing at low Reynolds number is not clear. We measured aerodynamic force on three types of airfoil with/without the propeller, and visualized flow field on the wing surface. From the results of force measurement, aerodynamic characteristics of the flat plate was almost unaffected by propeller stream. However aerodynamic characteristics of the Ishii airfoil and NACA0012 were changed by propeller slipstream. To see the results of visualization, the flow separation was prevented by the effect of propeller slipstream. These results caused the changes in aerodynamic characteristics.
Aerodynamic Characteristics and Effects of Winglets of the Boomless Tapered Supersonic Biplane during the Starting Process

YAMASHITA Hiroshi, FUJISONO Takashi, TOYODA Atsushi, NAGAI Hiroki, ASAI Keisuke, JEONG Shinkyu, OBAYASHI Shigeru

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN　11　(0)　17-26　2013
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/tastj.11.17 　

ISSN： 1884-0485

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The aerodynamic characteristics and the effects of tip plates of a tapered supersonic biplane wing during the starting process were investigated by experimental and computational fluid dynamics (EFD/CFD). Three types of wing models were used: one with a tip plate covering only the aft-half of the wing tip (type-A); one with a tip plate covering the entire wing tip (type-B); and one without a tip plate (type-N). Experiments were conducted in a supersonic blowdown wind tunnel 600 × 600 mm in cross-section located at the high-speed wind tunnel facility of the Institute of Space and Astronautical Science (ISAS/JAXA). The flow conditions ranged from M_∞ = 1.5 to 1.9 in increments of 0.1. Pressure-sensitive paint was applied to measure the pressure distributions on the wing surface. CFD simulations were conducted for comparison with the experimental results and for detailed investigation of the effects of the Mach number. The tapered biplane wing without a tip plate is found to start between M_∞ = 1.8 and 1.9. The difference in starting Mach number between type-N and type-A is small. On the other hand, the starting Mach number of type-B is approximately 0.05 higher than that of type-N.
Wind Tunnel Testing on Start/Unstart Characteristics of Finite Supersonic Biplane Wing Peer-reviewed

Hiroshi Yamashita, Naoshi Kuratani, Masahito Yonezawa, Toshihiro Ogawa, Hiroki Nagai, Keisuke Asai, Shigeru Obayashi

INTERNATIONAL JOURNAL OF AEROSPACE ENGINEERING　2013　2013

DOI： 10.1155/2013/231434 　

ISSN： 1687-5966

eISSN： 1687-5974
Aerodynamic Characteristics and Effects of Winglets of the Boomless Tapered Supersonic Biplane during the Starting Process

FUJISONO Takashi, YAMASHITA Hiroshi, TOYODA Atsushi, NAGAI Hiroki, ASAI Keisuke, JEONG Shinkyu, OBAYASHI Shigeru

JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES　60　(1)　1-8　2012/02/05
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/jjsass.60.1 　

ISSN： 1344-6460

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The aerodynamic characteristics and the effects of winglets of a tapered supersonic biplane during the starting process have been investigated through Experimental and Computational Fluid Dynamics (EFD/CFD). Three types of the tapered biplane model were used: without winglet (type-N); with the winglet which covers only the aft-half of the wing tip (type-A); with the winglet which covers the entire wing tip (type-B). Experiment was conducted in the supersonic blow-down wind tunnel with 600mm × 600mm cross section located at the High-speed Wind Tunnel Facility of Institute of Space and Astronautical Science, JAXA. The flow conditions covered from M_∞ = 1.5 to 1.9 with increments of 0.1. Pressure-Sensitive Paint was applied to measure pressure distributions on the surface of supersonic biplane models. CFD simulations were conducted to compare with experiment and to investigate effects of the Mach numbers in detail. The tapered biplane without the winglet was found to start between M_∞ = 1.8 and 1.9. The difference of the starting Mach numbers between type-N and type-A was small. On the other hand, the starting Mach number of type-B was about 0.05 higher than that of type-N.
Conceptual Design of Mars Airplane

FUJITA Koji, LUONG Remi, NAGAI Hiroki, ASAI Keisuke

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN　10　(28)　Te_5-Te_10　2012
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/tastj.10.Te_5 　

ISSN： 1884-0485

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The presence of an atmosphere on Mars signifies that an aircraft could travel in its atmosphere using the aerodynamic forces of flight. A reconnaissance aircraft offers the possibility to obtain high resolution data on a regional scale of several hundreds to thousands of kilometers, which cannot be achieved with rovers or satellites. However, conventional aircraft design cannot be applied for a Mars Airplane because of the nature of the Martian atmosphere and the constraints from transportation from Earth to Mars. This paper presents the conceptual design of a fixed-wing airplane for Mars, and the design rationale undertaken following the constraints set by the Martian environment. As a result, the main wing area was calculated to be 1.2 m². It was folded using two hinges to be packed into an aeroshell. The proposed Mars Airplane has four notches on its main wing. They make packing easier to keep the wing area maximized, making the Mars Airplane more compact.
Thermal Vacuum Testing of a Small Loop Heat Pipe with a PTFE Wick for Spacecraft Thermal Control

NAGANO Hosei, NISHIKAWARA Masahito, FUKUYOSHI Fuyuko, NAGAI Hiroki, OGAWA Hiroyuki

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN　10　(28)　Pc_27-Pc_33　2012
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/tastj.10.Pc_27 　

ISSN： 1884-0485

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A loop heat pipe (LHP) is a two-phase heat transfer device that utilizes the evaporation and condensation of a working fluid to transfer heat, and the capillary forces developed in fine porous wicks to circulate the fluid. LHPs have been gaining increased acceptance for spacecraft missions, and recently, small LHPs on the order of a few hundred watts have been investigated for this purpose. In this study, a 100W class small LHP with a polytetrafluoroethylene wick as the primary wick was designed and fabricated for thermal vacuum testing. The LHP has a thermoelectric converter (TEC) to control the loop operating temperature. The thermal vacuum test was conducted to evaluate the LHP's thermal performance under a space-simulated environment such as ultra-high-vacuum, and black body radiation, except for a gravitational effect. The loop showed large thermal hysteresis before and after the large and small head loads. The TEC was able to control the loop operating temperature with a small amount of electrical power.
Analysis of Shock-Wave Structures in a Supersonic Biplane by Focusing Schlieren Technique Peer-reviewed

萩原真澄, 永井大樹, 沼田大樹, 浅井圭介

JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES　60　(3)　142-148　2012
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/jjsass.60.142 　

ISSN： 1344-6460

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The flow field in a three dimensional biplane model is investigated by using a focusing schlieren method which can visualize a density gradient of arbitrary cross sections along a light path. Experiments were conducted in the 60mm×60mm indraft supersonic wind tunnel at the Institute of Fluid Science, Tohoku University at M_∞ = 1.7. Two test models were used in this experiment: the two-dimensional and three-dimensional models. First of all, the performance of the focusing schlieren system was evaluated by using the two dimensional model. The flow visualization in the three dimensional model is conducted by using the conventional schlieren method and more detail flow visualization by using the focusing schlieren method. Additionally, surface pressure distribution is measured by using the pressure-sensitive paint (PSP). From combined measurements, the flow field in the three dimensional model was discussed. It was found that shock wave structures in the test model vary in the span direction. Additionally, the cause of high pressure regions on the wing surface was understood by comparing with the PSP result.
Development of an experimental small loop heat pipe with polytetrafluoroethylene wicks Peer-reviewed

Hosei Nagano, Fuyuko Fukuyoshi, Hiroyuki Ogawa, Hiroki Nagai

Journal of Thermophysics and Heat Transfer　25　(4)　547-552　2011/10

DOI： 10.2514/1.T3614 　

ISSN： 0887-8722
Surface pressure and flow field behind an oscillating fence submerged in turbulent boundary layer Peer-reviewed

Manjinder Singh, Jonathan W. Naughton, Taro Yamashita, Hiroki Nagai, Keisuke Asai

Experiments in Fluids　50　(3)　701-714　2011/03

DOI： 10.1007/s00348-010-0977-y 　

ISSN： 0723-4864
Development of a Low-Density Wind Tunnel for Simulating Martian Atmospheric Flight

ANYOJI Masayuki, NOSE Kei, IDA Shingo, NUMATA Daiju, NAGAI Hiroki, ASAI Keisuke

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN　9　(0)　21-27　2011
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/tastj.9.21 　

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A new type of low-density wind tunnel called the “Mars Wind Tunnel (MWT)” has been developed to simulate airfoil flow in the Mars atmosphere. This paper presents the design features of the MWT and its construction. The results of operational performance tests including the driving performance of a multiple supersonic ejector and calibration tests for evaluating the flow characteristics in the test section are shown. These tests were conducted using air as the working gas. It was found that the ejector is an effective means to induce high subsonic flow even under the condition of a low Reynolds number. The pressure ratio achievable with the ejector is inversely proportional to the total pressure. The MWT can simulate flow in the Reynolds number range from 103 to 105 and Mach number up to 0.74. It is confirmed that the MWT has a flow quality and operational characteristics that are suitable for aerodynamic testing of Mars airplanes.
Multi-objective exploration of the launch condition for a fluctuating punted kick in rugby on the basis of PSP measurement Peer-reviewed

Kazuya Seo, Daisuke Yorita, Koji Shimoyama, Hiroki Nagai, Keisuke Asai

Procedia Engineering　2　(2)　2499-2504　2010/06

DOI： 10.1016/j.proeng.2010.04.022 　

ISSN： 1877-7058

eISSN： 1877-7058
Simulation of the trajectory of a punted rugby ball taking into account the asymmetrical pressure distribution caused by the seams Peer-reviewed

Kazuya Seo, Osamu Kobayashi, Masahide Murakami, Daisuke Yorita, Hiroki Nagai, Keisuke Asai

Journal of Visualization　13　(2)　97-105　2010/05

DOI： 10.1007/s12650-009-0019-0 　

ISSN： 1343-8875

eISSN： 1875-8975
Oxygen-sensing properties of 5, 10, 15, 20-tetraphenylporphinato platinum(II) and palladium(II) covalently bound on poly(isobutyl-co-2,2,2-trifluoroethyl methacrylate) Peer-reviewed

Makoto Obata, Noriko Matsuura, Kazunori Mitsuo, Hiroki Nagai, Keisuke Asai, Masafumi Harada, Shiho Hirohara, Masao Tanihara, Shigenobu Yano

Journal of Polymer Science, Part A: Polymer Chemistry　48　(3)　663-670　2010/02/01

DOI： 10.1002/pola.23818 　

ISSN： 0887-624X

eISSN： 1099-0518
Development of Multiple-Gas Analysis Method Using the Ball Surface Acoustic Wave Sensor

Hiroki Nagai

Japanese Journal of Applied Physics　2010

DOI： 10.1143/JJAP.49.07HD14 　
Simulation of the trajectory of a punted rugby ball taking into account the asymmetrical pressure distribution caused by the seams Peer-reviewed

Kazuya Seo, Osamu Kobayashi, Masahide Murakami, Daisuke Yorita, Hiroki Nagai, Keisuke Asai

Journal of Visualization　1　449-456　2010/01
Effect of Amount of Fluid Charge in Thermal Performance of Loop Heat Pipe Peer-reviewed

Hosei Nagano, Ei Onogawa, Fuyuko Fukuyoshi, Hiroyuki Ogawa, Hiroki Nagai

Heat Transfer- Asian Research　39　(6)　355-364　2010

DOI： 10.1002/htj.20306 　

ISSN： 1099-2871

eISSN： 1523-1496
Effect of Amount of Fluid Charge in Thermal Performance of Loop Heat Pipe

ONOGAWA Ei, NAGANO Housei, FUKUYOSHI Fuyuko, OGAWA Hiroyuki, NAGAI Hiroki

Thermal Science and Engineering　18　(1)　9-15　2010/01/01
Publisher: The Heat Transfer Society of Japan
DOI： 10.11368/tse.18.9 　

ISSN： 0918-9963

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Loop Heat Pipes (LHPs) are two-phase thermal control system, which works only by heat from its cooling target. In order to utilize the LHPs in various fields, it is requested to be smaller, more reliable, and higher performance. In the present study, a miniature LHP has been fabricated, and the effect of amount of working fluid charged on thermal performance of the LHPs has been investigated. Tests were conducted including start-up, power step up, as function of amount of working fluid. The test results showed that under-charging of working fluid caused start-up failure, while over-charging of working fluid made the LHP less stable.
Improvement in Operating Characteristics of a Small Loop Heat Pipe with Active Control of a Reservoir Peer-reviewed

福吉芙由子, 長野方星, 小川博之, 永井大樹

日本航空宇宙学会誌　2010
Characteristics of the Mars Wind Tunnel at Tohoku University in CO2 Operation Mode

ANYOJI, M, IDA, S, NOSE, K, NUMATA, D, NAGAI, H, ASAI, K

48th AIAA Aerospace Science Meeting and Exhibit　2010/01

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AIAA-2010-1490
Effect of temperature-sensitive-paint thickness on global heat transfer measurement in hypersonic flow Peer-reviewed

H. Nagai, S. Ohmi, K. Asai, K. Nakakita

Journal of Thermophysics and Heat Transfer　22　(3)　373-381　2008/07

DOI： 10.2514/1.34152 　

ISSN： 0887-8722
Pressure-sensitive paint measurement of pressure distribution in a supersonic micronozzle Peer-reviewed

H. Nagai, R. Naraoka, K. Sawada, K. Asai

AIAA Journal　46　(1)　215-222　2008/01

DOI： 10.2514/1.28371 　

ISSN： 0001-1452
Study on Thermal Performances of a Small Loop Heat Pipe

NAGANO Hosei, NAGAI Hiroki, FUKUYOSHI Fuyuko, OGAWA Hiroyuki

Journal of Thermal Science and Technology　3　(2)　355-367　2008

DOI： 10.1299/jtst.3.355 　

ISSN： 1880-5566
Development of luminescent differential-pressure sensor based on porous membrane Peer-reviewed

Yorita Daisuke, Nagai Hiroki, Asai Keisuke

Transactions of the Visualization Society of Japan　28　(4)　21-26　2008
Publisher: The Visualization Society of Japan
DOI： 10.3154/tvsj.28.21 　

ISSN： 1346-5260

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Pressure-Sensitive Paint (PSP) is applied to various wind tunnel tests as a useful technique to measure pressure distribution on model surfaces. PSP is inherently an absolute pressure sensor so that it is difficult to use this technique in low-speed flow where pressure change on a model is very small. To measure pressure with a high degree of accuracy at low speeds, we have developed a new type of PSP that responds to differential pressure rather than absolute pressure. This novel technique uses porous membrane through which gas containing no oxygen (e.g. nitrogen) is transported from the backside to the front side by pressure difference across the membrane. The transported gas purges oxygen near the surface and luminescence of PSP is enhanced. The results of sample tests show that the pressure sensitivity of the new PSP is higher than that of the conventional PSP by a factor of 100 times or more. In addition, the response of this sensor to differential pressure is almost linear and highly reproducible.
Pressure-sensitive paint measurement of the flow around a simplified car model Peer-reviewed

T. Yamashita, H. Sugiura, H. Nagai, K. Asai, K. Ishida

Journal of Visualization　10　(3)　289-298　2007

DOI： 10.1007/BF03181696 　

ISSN： 1343-8875
Evaluation of lifetime-based Pressure-Sensitive Paint measurement in low-speed flow Peer-reviewed

Taro Yamashita, Hiroki Nagai, Keisuke Asa

2007 22ND INTERNATIONAL CONGRESS ON INSTRUMENTATION IN AEROSPACE SIMULATION FACILITIES　100-109　2007

DOI： 10.1109/ICIASF.2007.4380884 　

ISSN： 0730-2010
Measurement of oxygen partial pressure distribution in a fuel cell using pressure-sensitive paint Peer-reviewed

Suguru Inagaki, Hiroki Nagai, Keisuke Asai

2007 Proceedings of the ASME/JSME Thermal Engineering Summer Heat Transfer Conference - HT 2007　2　77-83　2007

DOI： 10.1115/HT2007-32751 　
Thermal performance of a miniature loop heat pipe for spacecraft thermal control system Peer-reviewed

Hiroki Nagai, Hosei Nagano, Fuyuko Fukuyoshi, Hiroyuki Ogawa

2007 Proceedings of the ASME/JSME Thermal Engineering Summer Heat Transfer Conference - HT 2007　3　721-726　2007

DOI： 10.1115/HT2007-32805 　
Experimental study of lambda-phase transition induced by shock compression Peer-reviewed

Y Ueta, K Yanaka, M Murakami, H Nagai, HS Yang

CRYOGENICS　42　(10)　645-651　2002/10

DOI： 10.1016/S0011-2275(02)00082-6 　

ISSN： 0011-2275
Experiments of highly transient thermo-fluid dynamic phenomena in HeII induced by gas dynamic shock wave impingement Peer-reviewed

H Nagai, HS Yang, Y Ueta, K Yanaka, M Murakami

ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B　613　1327-1334　2002

ISSN： 0094-243X
Study of thermal shock wave in shock-compressed HeII induced by gas dynamic shock wave impingement Peer-reviewed

HS Yang, Y Ueta, H Nagai, M Murakami, K Yanaka

ADVANCES IN CRYOGENIC ENGINEERING, VOL 47, PTS A AND B　613　1380-1387　2002

ISSN： 0094-243X
Study of the Measurement Technique for Liquid Volume in Micro-gravity

NAKANO Akihiro, MUTOU Miki, FUJIYAMA Junichi, NAGAI Hiroki, MURAKAMI Masahide

JASMA　18　(4)　263-268　2001/10/01
Publisher:
ISSN： 0915-3616
Application of superfluid shock tube facility to experiments of highly transient low-temperature thermo-fluid dynamic phenomena Peer-reviewed

H Nagai, HS Yang, Y Ueta, M Murakami, N Takano, K Yanaka

CRYOGENICS　41　(5-6)　421-428　2001/05

DOI： 10.1016/S0011-2275(01)00109-6 　

ISSN： 0011-2275

eISSN： 1879-2235
Temperature Measurement Study of Shock Waves in He II Induced by a Gas Dynamic Shock Wave Impingement.

YANG Hyung Suk, NAGAI Hiroki, MURAKAMI Masahide, UETA Yasuhiro

TEION KOGAKU (Journal of Cryogenics and Superconductivity Society of Japan)　36　(1)　2-9　2001
Publisher: CRYOGENICS AND SUPERCONDUCTIVITY SOCIETY OF JAPAN
DOI： 10.2221/jcsj.36.2 　

ISSN： 0389-2441

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Two modes of shock waves propagating in He II, that is, a compression and a thermal shock waves, were investigated by a measurement of temperature and pressure with superconductive temperature sensors and pressure transducers and by visualization. We adopted the experimental method in which a gas dynamic shock wave impinged onto a He II-free surface by a newly developed superfluid shock tube facility. It was found that the temperature sharply drops as a result of compression by a compression shock wave. However, the temperature drop turns to a rise when the phase of liquid helium changes from He II to He I by shock compression. It was also found that in the immediate vicinity of the vapor-He II interface, no thermal shock wave is excited, where a thermal boundary layer with a large temperature gradient in which the physical state changes from supercritical helium to He II via He I is formed with a thickness of several mm. The temperature profile of a thermal shock wave was found to be a single triangular waveform similar to that of a thermal shock wave generated by large heat flux by a planar heater with a long heating time.
Epitaxial growth properties of Si and SiGe films prepared by ion beam sputtering process

Hiroki Nagai

Vacuum　2000

DOI： 10.1016/S0042-207X(00)00293-1 　
Study of Shock Waves and Phase Transition in He II by using Superfluid Shock Tube Facility Peer-reviewed

NAGAI, H, TAKANO, N, YANG, H.S, MURAKAMI, M

Advances in Cryogenic Engineering　45　1049-1056　2000
Experimental Investigation of Thermal Shock Wave induced by Gas Dynamic Shock Wave Impingement Peer-reviewed

YANG, H.S, NAGAI, H, TAKANO, N, MURAKAMI, M

Advances in Cryogenic Engineering　45　1057-1064　2000
Investigation of two modes of shock wave in He II by using newly developed superfluid shock tube facility Peer-reviewed

H Nagai, H Yang, N Takano, M Murakami

INTERNATIONAL CRYOGENIC ENGINEERING CONFERENCE 1998　843-846　1998
Visualization study of phase transitions of He II induced by shock wave compression Peer-reviewed

N Takano, H Nagai, H Yang, M Murakami

INTERNATIONAL CRYOGENIC ENGINEERING CONFERENCE 1998　691-694　1998
Development of superfluid shock tube facility Peer-reviewed

H Nagai, M Murakami, H Yang, N Takano, S Teraoka

ADVANCES IN CRYOGENIC ENGINEERING, VOL 43 PTS A AND B　43　1393-1400　1998

ISSN： 0065-2482
Development and Performance Test Results of Superfluid Shock-tube Facility.

NAGAI Hiroki, YANG HyungSuk, TAKANO Nahoko, MURAKAMI Masahide

TEION KOGAKU (Journal of Cryogenics and Superconductivity Society of Japan)　33　(6)　403-409　1998
Publisher: CRYOGENICS AND SUPERCONDUCTIVITY SOCIETY OF JAPAN
DOI： 10.2221/jcsj.33.403 　

ISSN： 0389-2441

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The superfluid shock-tube facility has been developed as a versatile tool for general research of low-temperature thermo-fluid dynamic phenomena. The shock tube was designed to be operated with the He II-filled test section immersed in superfluid helium. A gasdynamic shock wave impinging onto a He II-free surface generates a transmitted compression shock wave (of first sound origin) and thermal shock wave (of second sound origin) as the genuine temperature wave in He II. The target physical phenomena in the He II are measured using pressure transducers and superconductive temperature sensors, by applying a laser beam refraction method and with the aid of some optical visualization methods. In this study, the general superfluid thermodynamic performance of shock waves in the facility is investigated to verify the validity of the facility under a wide range of experimental conditions.
Visualization study on the thermohydrodynamic phenomena induced by pulsative heating in He II by the use of a laser holographic interferometer Peer-reviewed

T Iida, M Murakami, T Shimazaki, H Nagai

CRYOGENICS　36　(11)　943-949　1996/11

DOI： 10.1016/S0011-2275(96)00075-6 　

ISSN： 0011-2275
Visualization study of highly transient thermo-fluid dynamic phenomena in He II Peer-reviewed

T Iida, M Murakami, T Shimazaki, H Nagai, T Furukawa

ADVANCES IN CRYOGENIC ENGINEERING, VOL 41, PTS A AND B　41　249-256　1996

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Misc. 490

Quantitative Density Measurement of Unsteady Flow Field around Re-Entry Capsule Model

井川将大, 高坂菜央, 猪狩優斗, 山岸雅人, 太田匡則, 稲毛達朗, 川野理人, 大谷清伸, 永井大樹

衝撃波シンポジウム講演論文集(CD-ROM)　2023　2024
Simultaneous Measurement of Three-Dimensional Density Field around Hayabusa Capsule Model and the Angle of Attack in a ballistic range

山岸雅人, 高坂菜央, 廣瀬裕介, 稲毛達朗, 宇田川真介, 太田匡則, 滝川侑弥, 大谷清伸, 永井大樹

衝撃波シンポジウム講演論文集(CD-ROM)　2023　2024
Gaseous Flow Measurement Method by Combining Pressure-Sensitive Paint and Sparse Sensing

R. Tanaka, T. Ikami, Y. Egami, H. Nagai, Y. Matsuda

914-915　2023/10
Comprehensive Study on Two-phase Thermo-fluid Phenomena in Cryogenic Loop Heat Pipe

小田切公秀, 永井大樹, 小川博之, 常新雨, 横内岳史

東北大学流体科学研究所共同利用・共同研究拠点流体科学国際研究教育拠点活動報告書(CD-ROM)　2022　2023
Density measurement around a Reentry capsule in Ballistic range

山岸雅人, 廣瀬裕介, 太田匡則, 細野陽太, 大谷清伸, 永井大樹

衝撃波シンポジウム講演論文集(CD-ROM)　2022　2023
極低温ループヒートパイプ内部の気液二相熱流動現象の包括的理解—Comprehensive Study on Two-phase Thermo-fluid Phenomena in Cryogenic Loop Heat Pipe

小田切公秀, 永井大樹, 小川博之, 常新雨, 横内岳史

共同利用・共同研究拠点「流体科学国際研究教育拠点」活動報告書 = Activity report Joint Usage/Research Center "Fluid Science Global Research and Education Hub"　141-143　2022
Publisher: [仙台] : 東北大学流体科学研究所
High-accurate density measurement around the Re-entry capsule model

片桐優太郎, 高坂菜央, 楢山仁, 山岸雅人, 廣瀬祐介, 太田匡則, 野村将之, 藤田昂志, 大谷清伸, 永井大樹

衝撃波シンポジウム講演論文集(CD-ROM)　2021　2022
Experimental Investigation on Aerodynamic Performance of Coaxial Rotor at Low Reynolds Numbers

Atsushi Yamaguchi, Raoul S. Golani, Koji Fujita, Hiroki Nagai

AIAA Scitech 2021 Forum　2021/01/11
Publisher: American Institute of Aeronautics and Astronautics
DOI： 10.2514/6.2021-1308 　
Validation of Sub-millimeter Resolution Pressure Measurement on Free Flight Model Mach 1.5

Joseph Gonzales, Daiki Kurihara, Hiroki Nagai, Hirotaka Sakaue, Aleksandar Jemcov

AIAA Scitech 2021 Forum　2021/01/11
Publisher: American Institute of Aeronautics and Astronautics
DOI： 10.2514/6.2021-0871 　
Permeable membrane wing characteristics at Reynolds number order of 10,000

Koji Fujita, Koichi Takahashi, Hiroki Nagai

AIAA Scitech 2021 Forum　2021/01/11
Publisher: American Institute of Aeronautics and Astronautics
DOI： 10.2514/6.2021-1086 　
Response Evaluation of cntTSP for Detection of Dynamic Boundary Layer Transition in Low-Speed Wind Tunnel

Tsubasa Ikami, Koji Fujita, Hiroki Nagai, Daisuke Yorita

AIAA Scitech 2021 Forum　2021/01/11
Publisher: American Institute of Aeronautics and Astronautics
DOI： 10.2514/6.2021-0329 　
Qualitative Density Measurement of Wake Region Behind Re-Entry Capsule

太田匡則, 永井大樹, 廣瀬裕介, 稲毛達朗, 大谷清伸

東北大学流体科学研究所共同利用・共同研究拠点流体科学国際研究教育拠点活動報告書(CD-ROM)　2020　2021
Application of Low-Temperature Sensitive Fast Response PSP on Low-Speed Unsteady Flow and Its Validation

江上泰広, 山崎遊野, 松田佑, 藤田昂志, 永井大樹

東北大学流体科学研究所共同利用・共同研究拠点流体科学国際研究教育拠点活動報告書　2019 (CD-ROM)　2021
Development of Plant-Bioatellite Cube-Unit (Plant-BioCube Unit) Mounted on Exposure Area at ISS Platform for Investigation of Plant Life Support Mechanisms in Space Environment

HIDEMA Jun, YOSHIYAMA Kaoru, KASABA Yasumasa, KUWAHARA Yoshinori, KUME Atsushi, NAGAI Hiroki, HASHIMOTO Hirofumi, INATOMI Yuko

(35)　2021/01
Publisher: Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)

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Space Utilization Research (January 19-20, 2021. Online Meeting)
第2回火星飛行機高高度飛行試験(MABE2)の準備状況(その2)

大山聖, 永井大樹, 藤田昂志, 安養寺正之, 岡本正人, 金崎雅博, 高野敦, 竹内伸介, 安部明雄, 佐々修一, 満武勝嗣, 得竹浩, 火星探査航空機リサーチグループ, OYAMA Akira, NAGAI Hiroki, FUJITA Koji, ANYOJI Masayuki, OKAMOTO Masato, KANAZAKI Masahiro, TAKANO Atsushi, TAKEUCHI Shinsuke, ABE Akio, SASA Syuichi, MITSUTAKE Katsushi, TOKUTAKE Hiroshi

大気球シンポジウム: 2020年度 = Balloon Symposium: 2020　2020/11
Publisher: 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)

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大気球シンポジウム 2020年度（2020年11月5-6日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)）, 相模原市, 神奈川県著者人数: 12名資料番号: SA6000151030レポート番号: isas20-sbs-030
弾道飛行装置実験により自由飛行するカプセルの遷音速域における後流の時空間構造の特徴抽出

桐谷英樹, 永井大樹, 藤田昂志, 大谷清伸

2019年度衝撃波シンポジウム講演論文集　2020/03
Noise Reduction Effect of Proper Orthogonal Decomposition and Dynamic Mode Decomposition for Unsteady PSP Measurements

森重聡一郎, 山崎遊野, 松田佑, 松田佑, 伊神翼, 永井大樹, 江上泰広

可視化情報シンポジウム(CD-ROM)　48th　2020

ISSN： 2433-2275
Development of discrete bubble model for prediction of flows inside of a heatpipe

高橋俊, 奈良祥太朗, 長島弘明, 竹村薫, 安達拓矢, 永井大樹, 岡崎峻, 福家英之

日本伝熱シンポジウム講演論文集(CD-ROM)　57th　2020

ISSN： 1346-1532
Current status and Japanese team activities of the GAPS experiment to survey cosmic-ray antinuclei

小財正義, 福家英之, 岡崎峻, 小川博之, 西城大, 徳永翔, 吉田哲也, 竹内崇人, 中上裕輔, 吉田篤正, 和田拓也, 清水雄輝, 山田昇, 小池貴久, 加藤千尋, 宗像一起, 永井大樹, 河内明子, 小林聖平, 五味颯雅, 近藤愛実, 高橋俊, 竹村薫, 田邉拓哉, 長島弘明, 水野広基, 井上剛良, HAILEY C.J., PEREZ K., FABRIS L., CRAIG W., ONG R., BOGGS S., DOETINCHEM P.v., BOEZIO M.

日本物理学会講演概要集(CD-ROM)　75　(1)　2020

ISSN： 2189-079X
Blade Element Theory Coupled with CFD Applied to Optimal Design of Rotor for Mars Exploration Helicopter

Kazufumi Uwatoko, Masahiro Kanazaki, Hiroki Nagai, Koji Fujita, Akira Oyama

AIAA Scitech 2020 Forum　2020/01

DOI： 10.2514/6.2020-1284 　
Deployable Wing Model Using ANCF and UVLM: Multibody Dynamic Simulation and Wind Tunnel Experiment International-coauthorship

Keisuke Otsuka, Yinan Wang, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

AIAA Scitech 2020 Forum　2020/01

DOI： 10.2514/6.2020-1678 　
Transonic Flow Field Analysis of a Free Flight Capsule using Ballistic Range

Hideki Kiritani, Naoki Tanaka, Kiyonobu Ohtani, Koji Fujita, Hiroki Nagai

AIAA Scitech 2020 Forum　2020/01

DOI： 10.2514/6.2020-1990 　
Parametric Study of Mars Helicopter for Pit Crater Exploration International-coauthorship

Koji Fujita, Hilal Karaca, Hiroki Nagai

AIAA Scitech 2020 Forum　2020/01

DOI： 10.2514/6.2020-1734 　
Experimental and RANS analysis of full Mars airplane configurations

Shota Taniguchi, Akira Oyama, M Okamoto, Masato Okamoto, Masayuki Anyoji, Koji Fujita, Hiroki Nagai

AIAA Scitech 2020 Forum　2020/01

DOI： 10.2514/6.2020-2224 　
自由飛行するカプセルの遷音速領域における後流の時空間構造の特徴抽出解析

永井大樹

令和元年度航空宇宙空力シンポジウム講演論文集　2020/01
第2回火星飛行機高高度飛行試験(MABE2)の準備状況

大山聖, 永井大樹, 藤田昂志, 安養寺正之, 岡本正人, 江光希, 谷口翔太, 田中寛人, 金崎雅博, 橘高洋人, 高野敦, 水上諒, 竹内伸介, 安部明雄, 佐々修一, 布田翼, 満武勝嗣, 得竹浩, 火星探査航空機リサーチグループ, Oyama Akira, Nagai Hiroki, Fujita Koji, Anyoji Masayuki, Okamoto Masato, Koh Mitsuki, Taniguchi Shota, Tanaka Hiroto, Kanazaki Masahiro, Kittaka Hiroto, Takano Atsushi, Mizukami Ryo, Takeuchi Shinsuke, Abe Akio, Sasa Shuichi, Futa Tsubasa, Mitsutake Katsushi, Tokutake Hiroshi

大気球シンポジウム: 2019年度 = Balloon Symposium: 2019　2019/11
Publisher: 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)

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大気球シンポジウム 2019年度（2019年11月7-8日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)）, 相模原市, 神奈川県著者人数: 18名資料番号: SA6000140008レポート番号: isas19-sbs-008
宇宙線反粒子探索GAPS実験計画の(特に日本チームの)現状報告

福家英之, 小財正義, 小川博之, 岡崎峻, 西城大, 徳永翔, 吉田哲也, 中上裕輔, 竹内崇人, 和田拓也, 吉田篤正, 清水雄輝, 山田昇, 小池貴久, 加藤千尋, 宗像一起, 永井大樹, 五味颯雅, 河内明子, 小林聖平, 近藤愛実, 水野広基, 長島弘明, 高橋俊, 竹村薫, 田邉拓哉, 井上剛良, Hailey Charles, Perez Kerstin, Fabris Lorenzo, Craig William, Ong Rene, Boggs Steven, Doetinchem Philip von, Boezio Mirko, Fuke Hideyuki, Kozai Masayoshi, Ogawa Hiroyuki, Okazaki Shun, Saijo Masaru, Tokunaga Kakeru, Yoshida Tetsuya, Nakagami Yusuke, Takeuchi Shuto, Wada Takuya, Yoshida Atsumasa, Shimizu Yuki, Yamada Noboru, Koike Takahisa, Kato Chihiro, Munakata Kazuoki, Nagai Hiroki, Gomi Soga, Kawachi Akiko, Kobayashi Shohei, Kondo Manami, Mizuno Koki, Nagashima Hiroaki, Takahashi Shun, Takemura Kaoru, Tanabe Takuya, Inoue Takayoshi, Hailey Charles, Perez Kerstin, Fabris Lorenzo, Craig William, Ong Rene, Boggs Steven, Doetinchem Philip von, Boezio Mirko

大気球シンポジウム: 2019年度 = Balloon Symposium: 2019　2019/11
Publisher: 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)

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大気球シンポジウム 2019年度（2019年11月7-8日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)）, 相模原市, 神奈川県著者人数: 35名資料番号: SA6000140039
飛翔体周りの非定常流れ場に対する定量的密度計測

太田匡則, 永井大樹, 栗原健, 稲毛達朗

東北大学流体科学研究所共同利用・共同研究拠点流体科学国際研究教育拠点活動報告書　2017　2019
Preliminary Conceptual Design of Mars Airplane for RSL Observation

藤田昂志, 永井大樹, 大山聖, 藤田和央

宇宙科学技術連合講演会講演集(CD-ROM)　63rd　2019

ISSN： 1884-1945
INTERNAL FLOW CHARACTERISTICS OF MULTI-EVAPORATOR LOOP HEAT PIPE

CHANG Xinyu, 渡邉紀志, 永井大樹, 小川博之, 長野方星

Thermophysical Properties　40th　2019

ISSN： 0911-1743
遷音速域における自由飛行カプセルの後流解析

桐谷英樹, 永田貴之, 永井大樹, 大谷清伸, 小川俊広

衝撃波シンポジウム講演論文集(CD-ROM)　2018　ROMBUNNO.1A3‐2　2019
Reentry capsule dynamic instability with different aft-body shape in transonic flow

Masayuki Nomura, Arthur Robbe, Koji Fujita, Hiroki Nagai

AIAA Scitech 2019 Forum　2019

DOI： 10.2514/6.2019-0018 　
Development of free flight experimental and analytical procedures for atmospheric entry vehicles

Olaseinde Jegede, Koji Fujita, Hiroki Nagai, Hideyuki Tanno

AIAA Scitech 2019 Forum　2019

DOI： 10.2514/6.2019-0019 　
Effects of rib number and rigid trailing edge on flexible-skinned thick wing at low reynolds number

Koji Fujita, Kenta Uechi, Koichi Takahashi, Hiroki Nagai

AIAA Scitech 2019 Forum　2019/01

DOI： 10.2514/6.2019-1893 　
Experimental study on high efficiency of aerodynamic performance of rotor blades for mars helicopter

Kensuke Kanou, Koji Fujita, Hiroki Nagai

AIAA Scitech 2019 Forum　2019

DOI： 10.2514/6.2019-2160 　
Flow field on wing surface with control surface in propeller slipstream at low reynolds number

Tsubasa Ikami, Kensuke Kanou, Koichi Takahashi, Koji Fujita, Hiroki Nagai

AIAA Scitech 2019 Forum　56th　ROMBUNNO.3A11　2019

DOI： 10.2514/6.2019-2159 　
MABE2: 第２回火星飛行機高高度飛行試験

大山聖, 永井大樹, 藤田昂志, 安養寺正之, 岡本正人, 江光希, 金崎雅博, 高野敦, 水上諒, 竹内伸介, 安部明雄, 佐々修一, 布田翼, 満武勝嗣, 得竹浩, 火星探査航空機リサーチグループ, Oyama Akira, Nagai Hiroki, Fujita Koji, Anyoji Masayuki, Okamoto Masato, Koh Mitsuki, Kanazaki Masahiro, Takano Atsushi, Mizukami Ryo, Takeuchi Shinsuke, Abe Akio, Sasa Shuichi, Futa Tsubasa, Mitsutake Katsushi, Tokutake Hiroshi

大気球シンポジウム: 平成30年度 = Balloon Symposium: 2018　2018/11
Publisher: 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)

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大気球シンポジウム平成30年度（2018年11月1-2日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県著者人数: 15名ほか資料番号: SA6000128031レポート番号: isas18-sbs-031
Wind Tunnel Test of Flexible Membrane Wing at Low Reynolds Number

藤田昂志, 上地健太, 高橋幸一, 永井大樹

日本航空宇宙学会年会講演会講演集(CD-ROM)　49　5p　2018/04/19
Publisher: 日本航空宇宙学会
Numerical study on high aerodynamic drag of a badminton shuttlecock

KOBAYASHI Masaki, HASEGAWA Hiroaki, NAGAI Hiroki

The Proceedings of the Symposium on sports and human dynamics　2018　(0)　C-9　2018
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmeshd.2018.C-9 　

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A badminton shuttlecock is an airborne projectile with a unique shape. The shuttlecock creates much higher drag, causing it to decelerate more rapidly than a ball. In the previous study, high aerodynamic characteristics of a badminton shuttlecock was examined in a wind tunnel, and it was confirmed that the gaps of shuttlecock were strongly related to high aerodynamic drag. However, it is difficult to investigate the flow through the gaps experimentally. In the present study, the numerical analysis on the flow behavior through the gaps of the shuttlecock with and without gaps is performed by using OpenFOAM method. The calculated drag is in good agreement with the experimental results. For the shuttlecock with gaps, the air flowed through the gaps in the shuttlecock skirt, and flow through the gaps behave like a jet. This flow causes a high drag because the pressure inside of the shuttlecock with gaps becomes lower than that of the shuttlecock with no gaps.
Aerodynamic characteristics of mars airplane airfoils with control surface in propeller slipstream

Kakeru Kurane, Kenta Uechi, Koichi Takahashi, Koji Fujita, Hiroki Nagai

AIAA Aerospace Sciences Meeting, 2018　(210059)　2018

DOI： 10.2514/6.2018-2058 　
Conceptual helicopter design for exploration of pit craters and caves on mars

Risako Aoki, Akira Oyama, Koji Fujita, Hiroki Nagai, Kensuke Kanou, Nao Inoue, Shu Sokabe, Masahiro Kanazaki, Kai Tomisawa, Kazufumi Uwatoko

2018 AIAA SPACE and Astronautics Forum and Exposition　2018

DOI： 10.2514/6.2018-5362 　
Monte-Carlo evaluation of control law for high altitude flight test of Mars airplane

Koji Fujita, Hiroki Nagai, Hiroshi Tokutake, Akira Oyama

31st Congress of the International Council of the Aeronautical Sciences, ICAS 2018　2018
弾道飛行装置における3次元密度計測の試み

栗原健, 志田輝一, 石川和樹, 石本祥之, 永島拓己, 稲毛達郎, 太田匡則, 永井大樹

衝撃波シンポジウム講演論文集(CD-ROM)　2017　ROMBUNNO.1A2‐2　2018
Effects of Propeller Slipstream to Mars Airplane Main Wing

永井大樹, 倉根翔, 上地健太, 高橋幸一, 藤田昂志

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　50th-36th　ROMBUNNO.2B12　2018
An Attempt of Oscillation Analysis of Free-Fall Test for Hayabusa and HRV Capsules

藤田昂志, JEGEDE Olaseinde, 永井大樹, 丹野英幸

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　50th-36th　ROMBUNNO.2C06　2018
Preliminary Conceptual Design of Rotorcraft for Martian Hole Exploration

藤田昂志, POMAR Guillaume, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　62nd　ROMBUNNO.1C16　2018

ISSN： 1884-1945
Performance Test of Co-axial Rotor of Mars Helicopter for Vertical Hole Exploration on Mars

加納健佑, 藤田昂志, 永井大樹

飛行機シンポジウム講演集(CD-ROM)　56th　ROMBUNNO.3B13　2018
Study on Improvement of Start-up Characteristics of Oscillating Heat Pipe by Check Valve Layout

松友瑠以, 安藤麻紀子, 岡本篤, 田中洸輔, 杉田寛之, 五十幡大地, 井上菜生, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　62nd　ROMBUNNO.3F07　2018

ISSN： 1884-1945
宇宙機の熱・流体制御技術の最前線

永井大樹, 大丸拓郎, 安達拓矢

日本伝熱シンポジウム講演論文集(CD-ROM)　55th　ROMBUNNO.J235　2018

ISSN： 1346-1532
Influence of the Capsule Aft-body Shape on the Dynamic Instability in Transonic Flow

野村将之, 藤田昂志, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　62nd　ROMBUNNO.2L17　2018

ISSN： 1884-1945
Evaluation of the Effect of the Reentry Capsule Aft-Body Shape on Dynamic Instability by Wind Tunnel Experiment

野村将之, ROBBE Arthur, 藤田昂志, 永井大樹

飛行機シンポジウム講演集(CD-ROM)　56th　ROMBUNNO.3A12　2018
Analysis of Dynamic Behavior of Re-entry Capsule by Free Fall Test

丹野茉莉枝, 藤田昂志, 永井大樹, JEGEDE Olaseinde, 丹野英幸

宇宙科学技術連合講演会講演集(CD-ROM)　62nd　ROMBUNNO.2L20　2018

ISSN： 1884-1945
Mars Exploration by Mars Airplane

永井大樹, 大山聖

宇宙科学技術連合講演会講演集(CD-ROM)　62nd　ROMBUNNO.1C10　2018

ISSN： 1884-1945
Attempts to improve the startup characteristics with the aim of the high-reliability of Oscillating Heat Pipe for space application

井上菜生, 永井大樹, 安藤麻紀子, 松友瑠以, 岡本篤, 杉田寛之

宇宙科学技術連合講演会講演集(CD-ROM)　62nd　ROMBUNNO.3F08　2018

ISSN： 1884-1945
Numerical Study of the Relation between the Internal Flow of a Loop Heat Pipe and Cause of Temperature Oscillation

安達拓矢, 藤田昂志, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　62nd　ROMBUNNO.3F05　2018

ISSN： 1884-1945
Dynamic Visualization of Boundary-Layer Transition in a Pitch-Sweep Test using a Carbon Nanotube TSP

依田大輔, LEMARECHAL Jonathan, KLEIN Christian, 藤田昂志, 永井大樹

可視化情報シンポジウム(CD-ROM)　46th　ROMBUNNO.053　2018

ISSN： 2433-2275
Numerical study on improvement of startup characteristics of Oscillating Heat Pipe

井上菜生, 藤田昂志, 永井大樹

混相流シンポジウム講演論文集(Web)　2018　WEB ONLY　2018
Influence of Check Valve Layout on Start-up Characteristics of Oscillating Heat Pipe

安藤麻紀子, 五十幡大地, 松友瑠以, 岡本篤, 田中洸輔, 杉田寛之, 井上菜生, 永井大樹

混相流シンポジウム講演論文集(Web)　2018　WEB ONLY　2018
Numerical Investigation of the Influence of Condensation Length during Temperature Oscillation in a Loop Heat Pipe

安達拓矢, 平田拓巳, 藤田昂志, 永井大樹

混相流シンポジウム講演論文集(Web)　2018　WEB ONLY　2018
宇宙機の熱・流体制御の最前線 Invited Peer-reviewed

Hiroki Nagai, Takuya Adachi, Takurou Daimaru

伝熱　57　(238)　23‐30　2018/01/01

ISSN： 1344-8692
Unsteady PSP/TSP Measurement Techniques Invited Peer-reviewed

NAKAKITA Kazuyuki, SUGIOKA Yosuke, NAGAI Hiroki

Journal of the Visualization Society of Japan　38　(148)　3-9　2018
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.38.148_3 　

ISSN： 0916-4731

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Fundamental elements for the unsteady PSP/TSP measurement, which were measurement hardware, paint, and data reduction method, were introduced in this paper. Especially, difference from the conventional PSP/TSP measurement in papers in the special issues were described in detail. Important researches for the unsteady PSP/TSP measurement progress were picked up to understand key points of the technologies. Recent progresses in PSP/TSP paint developments and data reduction methods were also introduced.
PSP and TSP Application in Aerospace Fields Invited Peer-reviewed

NAGAI Hiroki, MITSUO Kazunori, NAKAKITA Kazuyuki, SUGIOKA Yosuke, OZAWA Hiroshi, YORITA Daisuke

Journal of the Visualization Society of Japan　38　(148)　17-24　2018
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.38.148_17 　

ISSN： 0916-4731

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Measurement technique using Pressure-Sensitive Paint (PSP) has already been utilized in practical wind tunnel tests in aircraft development because of a large amount of information in pressure distribution measurement. Temperature-Sensitive Paint (TSP) has also been developed in the aerospace field to correct the temperature of the PSP. This technique is also applied to the measurement of the aerodynamic heating rate generated at hypersonic speed, and it is expected to be applied to databases that contribute to the design of spacecraft. In this paper, we introduce the state-of-the-art practical applications of these PSP/TSP measurement technique. It also touches development trends in the aerospace field of PSP/TSP in Europe.
Application of Phosphorescence Measurement outside Aerospace Field Invited Peer-reviewed

KAMACHI Toshiaki, ITO Hidehiro, NAGAI Hiroki, MORI Hideo, OGURI Kazumasa, KITAZATO Hiroshi, OBATA Makoto

Journal of the Visualization Society of Japan　38　(148)　25-31　2018
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.38.148_25 　

ISSN： 0916-4731

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This review summaries the application of phosphorescence measurement for the various fields except for aerospace field. Especially we focused on the application to fuel cell, turbomachinery , biogeochemical processes in aquatic environments, medical field, and single cell analysis.
カプセル形状模型を用いた動的安定落下試験

丹野英幸, 小室智幸, 山田哲哉, 永井伸治, 永井大樹

日本機械学会年次大会講演論文集(CD-ROM)　2017　ROMBUNNO.S1910101　2017/09/02
Aerodynamic Heating Measurement using Temperature-Sensitive Paint with Light-Shielding Layer aimed at application to High-Enthalpy Shock Tunnel

兎内龍也, 長山剛大, 永井大樹

可視化情報学会誌　37　(Suppl.1(CD-ROM))　ROMBUNNO.F111　2017/07

ISSN： 0916-4731
Attitude Estimation on Mars Airplane Balloon Experiment-1 (MABE-1)

得竹浩, 藤田昂志, 大山聖, 永井大樹

日本航空宇宙学会年会講演会講演集(CD-ROM)　48　4p　2017/04/13
Publisher: 日本航空宇宙学会
Overview of Mars Airplane Balloon Experiment-1 (MABE-1)

大山聖, 永井大樹, 得竹浩, 藤田昂志, 安養寺正之, 豊田裕之, 宮澤優, 米本浩一, 岡本正人, 野々村拓, 元田敏和, 竹内伸介, 鎌田幸男, 大槻真嗣, 浅井圭介, 藤井孝藏

年会講演会講演集　48　8p　2017/04/13
Publisher: 日本航空宇宙学会
Evolutionary Computation Approach to Control Parameter Optimization of Mars Airplane Balloon Experiment-1 (MABE-1)

藤田昂志, 永井大樹, 得竹浩, 大山聖

年会講演会講演集　48　5p　2017/04/13
Publisher: 日本航空宇宙学会
Aerodynamic Characteristics on Mars Airplane Balloon Experiment-1 (MABE-1)

安養寺正之, 岡本正人, 藤田昂志, 永井大樹, 大山聖

年会講演会講演集　48　7p　2017/04/13
Publisher: 日本航空宇宙学会
Thermal Analysis of Mars Airplane on Mars Airplane Balloon Experiment-1 (MABE-1)

永井大樹, 小田泰之, 大丸拓郎, 大山聖, 藤田昂志

年会講演会講演集　48　8p　2017/04/13
Publisher: 日本航空宇宙学会
Aerodynamic Data Acquisition of Mars Airplane by High Altitude Flight Test

大山聖, 永井大樹, 得竹浩, 藤田昂志, 安養寺正之, 豊田裕之, 宮澤優, 米本浩一, 岡本正人, 野々村拓, 野々村拓, 元田敏和, 竹内伸介, 鎌田幸男, 大槻真嗣, 浅井圭介, 藤井孝藏, 藤井孝藏

宇宙航空研究開発機構研究開発報告 JAXA-RR-(Web)　(16-008)　69‐80 (WEB ONLY)　2017/03/14

ISSN： 2433-2216
次世代高温センサ研究会(フェーズ2)

内一哲也, 坂本敏昭, 三木寛之, 青木孝行, 秋宗淑雄, 小島純一, 荒川敬弘, 山下卓哉, 井元尚充, 古村一朗, 蝦名武雄, 森永雅彦, 米津豊作, 金澤兼治, 永井大樹, 高木敏行, 小助川博之

東北大学流体科学研究所共同利用・共同研究拠点流体科学研究拠点活動報告書　2015　187‐188　2017/03
Global heat flux measurement using temperature-sensitive paint in high-enthalpy shock tunnel HIEST Peer-reviewed

Takehiro Nagayama, Hiroki Nagai, Hideyuki Tanno, Tomoyuki Komuro

AIAA SciTech Forum - 55th AIAA Aerospace Sciences Meeting　2017

DOI： 10.2514/6.2017-1682 　
Numerical Study on Operational Characteristics of Oscillating Heat Pipe with Check Valves

井上菜生, 安達拓矢, 永井大樹, 岡崎俊, 小川博之

宇宙科学技術連合講演会講演集(CD-ROM)　61st　ROMBUNNO.3F05　2017

ISSN： 1884-1945
進化計算に基づく火星飛行機の高高度飛行試験(MABE‐1)の制御パラメータ最適化

藤田昂志, 永井大樹, 得竹浩, 大山聖

日本航空宇宙学会年会講演会講演集(CD-ROM)　48th　ROMBUNNO.1A16　2017
低レイノルズ数におけるプロペラ後流中の舵効きの空力特性

倉根翔, 上地健太, 高橋幸一, 永井大樹

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　49th-35th　ROMBUNNO.2A09　2017
火星飛行機の高高度飛行試験(MABE‐1)における機体システムの熱解析

永井大樹, 小田泰之, 大丸拓郎, 大山聖, 藤田昂志

日本航空宇宙学会年会講演会講演集(CD-ROM)　48th　ROMBUNNO.1A19　2017
Evaluation of Influence of Check Valves Layout on Start-up Characteristics of Oscillating Heat Pipe

五十幡大地, 森野美樹, 岡本篤, 安藤麻紀子, 田中洸輔, 杉田寛之, 大丸拓郎, 井上菜生, 永井大樹, 松友瑠以

宇宙科学技術連合講演会講演集(CD-ROM)　61st　ROMBUNNO.3F06　2017

ISSN： 1884-1945
火星飛行機の高高度飛行試験(MABE‐1)における空力特性

安養寺正之, 岡本正人, 藤田昂志, 永井大樹, 大山聖

日本航空宇宙学会年会講演会講演集(CD-ROM)　48th　ROMBUNNO.1A17　2017
Mars Airplane Design for the Next Balloon Experiment and Its Aerodynamic Characteristics Using CFD

富澤海, 藤田昂志, 大山聖, 永井大樹, 金崎雅博

宇宙科学技術連合講演会講演集(CD-ROM)　61st　ROMBUNNO.2B18　2017

ISSN： 1884-1945
Thermal Analysis of Temperature Oscillation at Start-up in a Loop Heat Pipe

安達拓矢, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　61st　ROMBUNNO.3F01　2017

ISSN： 1884-1945
感温塗料を用いた高温衝撃風洞HIESTにおける境界層遷移の可視化

永井大樹, 長山剛大, 丹野英幸, 小室智幸

衝撃波シンポジウム講演論文集(CD-ROM)　2016　ROMBUNNO.2A1‐4　2017
火星飛行機の高高度飛行試験(MABE‐1)の概要

大山聖, 永井大樹, 得竹浩, 藤田昂志, 安養寺正之, 豊田裕之, 宮澤優, 米本浩一, 岡本正人, 野々村拓, 野々村拓, 元田敏和, 竹内伸介, 鎌田幸男, 大槻真嗣, 浅井圭介, 藤井孝藏, 藤井孝藏

日本航空宇宙学会年会講演会講演集(CD-ROM)　48th　ROMBUNNO.1A15　2017
Evaluation of control law for high altitude flight test of Mars airplane using Monte-Carlo simulation

藤田昂志, 大山聖, 得竹浩, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　61st　ROMBUNNO.2B17　2017

ISSN： 1884-1945
Influence of Flow Resistance of Check Valve on Thermal Performance of Oscillating Heat Pipe

井上菜生, 大丸拓郎, 永井大樹, 安藤麻紀子, 田中洸輔, 岡本篤, 杉田寛之, 五十幡大地

混相流シンポジウム講演論文集(CD-ROM)　2017　ROMBUNNO.E112　2017
Conceptual Design of Helicopter for Exploring Vertical Holes on Mars

青木理紗子, 大山聖, 藤田昂志, 永井大樹, 加納健佑, 井上菜生, 曽我部崇, 金崎雅博

宇宙科学技術連合講演会講演集(CD-ROM)　61st　ROMBUNNO.2B12　2017

ISSN： 1884-1945
低レイノルズ数における柔軟膜構造翼の空力特性と膜変形の影響

上地健太, 倉根翔, 高橋幸一, 永井大樹

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　49th-35th　ROMBUNNO.2A14　2017
翼型の最適化を用いたロータブレードの効率化に関する研究

加納健佑, 三坂孝志, 永井大樹, 仲野是克, 大林茂, 石川満, 茅沼秀高

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　49th-35th　ROMBUNNO.1D02　2017
On the current status of Mars Flight Exploration

永井大樹, 大山聖, 山田和彦

宇宙科学技術連合講演会講演集(CD-ROM)　61st　ROMBUNNO.2B10　2017

ISSN： 1884-1945
Investigation of Feasibility of Multicopter for Mars Exploration

野村将之, 安達拓矢, 上地健太, 倉根翔, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　61st　ROMBUNNO.2B11　2017

ISSN： 1884-1945
Aerodynamic Characteristics of Badminton Shuttlecock with Forced Spin

FUJISAWA Yuki, OKI Daizen, HASEGAWA Hiroaki, MURAKAMI Masahide, NAGAI Hiroki

The Proceedings of the Symposium on sports and human dynamics　2017　(0)　B-21　2017
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmeshd.2017.B-21 　

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Badminton is one of the popular sports around the world and is the sport having the fastest initial velocity of a batted ball in all ball games. The initial velocity of the badminton shuttlecock reaches up to 408 km/h (113 m/s) at maximum. A shuttlecock has high deceleration characteristics as an airborne projectile and is extremely aerodynamically stable for the flip movement just after impact. These features of the shuttlecock have been the subject of research from the point of view of aerodynamics. In our previous study, it was confirmed that the air flows through the gaps in the shuttlecock skirt was strongly related to high aerodynamic drag. The purpose of this study is to investigate the effect of spin on aerodynamic characteristics of a badminton shuttlecock. The aerodynamic forces were measured for the shuttlecock with spin at several rotational speeds using a force balance in a wind tunnel test. The drag of the shuttlecock with spin increases with increasing rotational speed because the expansion of the skirt diameter is promoted due to a large centrifugal force given by the high rotational speed of the shuttlecock, and the drag force generation is not affected by the spin itself.
Dynamic stability drop tests with capsule shaped model

TANNO Hideyuki, KOMURO Tomoyuki, YAMADA Tetsuya, NAGAI Shinji, NAGAI Hiroki

The Proceedings of Mechanical Engineering Congress, Japan　2017　(0)　S1910101　2017
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecj.2017.S1910101 　

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A free-flight drop test is planned to evaluate aerodynamic stability of reentry capsules under subsonic condition. The final goal of the work is to obtain benchmarks of stability characteristics to compare with wind tunnel test results or CFD calculations. The model is a scaled models of a Japanese small reentry capsule, which diameter were 250mm. Nine onboard accelerometer modules are instrumented in the model to determine six-components aerodynamic characteristics. In the pre-drop test, acceleration histories are successfully measured with the onboard instruments, which demonstrates the feasibility of the present measurement scheme.
Recent progress of the GAPS experiment

Kozai Masayoshi, Asao Yoshito, Inoue Takayoshi, Inoue Takuya, Okazaki Shun, Ogawa Hiroyuki, Kato Chihiro, Kawachi Akiko, Koike T., Sakimoto Kazuhiro, Shimizu Yuki, Takahashi Katsumasa, Takahashi Shun, Daimaru Takuro, Nagai Hiroki, Hashimoto Takeshi, Fuke Hideyuki, Munakata Kazuoki, Yamada Noboru, Yoshida Atsumasa, Yoshida Tetsuya, Wada Takuya, Aramaki T., Boggs S., Craig W. W., Doetinch P.v., Fabris R., Gahbauer F., Hailey C.J., Madden N., Mognet S.A.I, Mori K., Ong R., Perez K., Ziock K.P., Zweerink J.

2016/11
Publisher: Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS)

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Balloon Symposium 2016 (November 1-2, 2016. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan
Evaluation of effect of a secondary wick on thermal performance of a loop heat pipe using simple mathematical model

安達拓矢, 大丸拓郎, 永井大樹

宇宙科学技術連合講演会講演集　60　6p　2016/09/06
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
Consideration on Startup Behavior in On-orbit Experiment of Oscillating Heat Pipe with Check Valves

大丸拓郎, 永井大樹, 安藤麻紀子, 田中洸輔, 岡本篤, 杉田寛之

宇宙科学技術連合講演会講演集　60　6p　2016/09/06
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
System trade-off analysis of two-phase mechanically pumped fluid loop for thermal control of future deep space missions

坂元健一, 大丸拓郎, 永井大樹, Sunada Eric, Bhandari Pradeep, Furst Benjamin, Cappucci Stefano

宇宙科学技術連合講演会講演集　60　6p　2016/09/06
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
Temperature Prediction of Mars Airplane Balloon Experiment-1 (MABE-1)

小田泰之, 大丸拓郎, 永井大樹

宇宙科学技術連合講演会講演集　60　6p　2016/09/06
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
Application and Evaluation of Temperature-Sensitive Paint to High Enthalpy Shock Tunnel

長山剛大, 永井大樹, 丹野英幸, 小室智幸

可視化情報学会誌　36　(Suppl.1(CD-ROM))　ROMBUNNO.A204　2016/07

ISSN： 0916-4731
Research and Development Trend on Supersonic and Hypersonic Aerodynamic Decelerator in the world

永井大樹

年会講演会講演集　47　3p　2016/04/14
Publisher: 日本航空宇宙学会
高温衝撃風洞HIESTへの適用を目指した感温塗料(TSP)の改良とその実証試験結果

長山剛大, 洞桐健人, 永井大樹, 丹野英幸, 小室智幸

宇宙航空研究開発機構特別資料 JAXA-SP-　(15-020(CD-ROM))　ROMBUNNO.P07　2016/03

ISSN： 1349-113X
南極周回気球による宇宙線反粒子探索計画GAPS

福家英之, 井上剛良, 加藤千尋, 河内明子, 小池貴久, 宗像一起, 永井大樹, 野々村拓, 小川博之, 岡崎峻, 崎本一博, 清水雄輝, 高橋俊, 山田昇, 吉田篤正, 吉田哲也, Boggs S., Craig W. W., Doetinchem P. v., Fabris R., Hailey C. J., Ong R., Perez K., Fuke Hideyuki, Inoue Takayoshi, Kato Chihiro, Kawachi Akiko, Koike T, Munakata Kazuoki, Nagai Daiki, Nonomura Taku, Ogawa Hiroyuki, Okazaki Shun, Sakimoto Kazuhiro, Shimizu Yuki, Takahashi Shun, Yamada Noboru, Yoshida Atsumasa, Yoshida Tetsuya, Boggs S., Craig W. W., Doetinchem P. v., Fabris R., Hailey C. J., Ong R., Perez K.

第16回宇宙科学シンポジウム講演集 = Proceedings of the 16th Space Science Symposium　2016/01
Publisher: 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)

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第16回宇宙科学シンポジウム (2016年1月6日-7日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)相模原キャンパス), 相模原市, 神奈川県著者人数: 23名資料番号: SA6000046257レポート番号: S5-009
Experimental Study of Effects of Secondary Wick Configuration on Thermal Performance of Loop Heat Pipe

NAGAI Hiroki, TAKETANI Masahiko, ADACHI Takuya, DAIMARU Takurou

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN　14　(30)　Pi_7-Pi_15　2016
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/tastj.14.Pi_7 　

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In this study, we experimentally investigated the effects of the secondary wick configuration on the thermal performance of a loop heat pipe (LHP). The results indicated that two important factors affect the heat transfer characteristics: (1) contact area between the secondary wick and the reservoir, and (2) cross-sectional area of evaporator core. We then propose a desirable secondary wick configuration by considering these two factors.
Development of a Cooling System for GAPS using Oscillating Heat Pipe

FUKE Hideyuki, MIYAZAKI Yoshiro, MORI Junichi, NAGAI Hiroki, NONOMURA Taku, OGAWA Hiroyuki, OKAZAKI Shun, OKUBO Takuma, OZAKI Shinji, SATO Daisuke, SHIMIZU Kensei, ABE Takumi, TAKAHASHI Katsumasa, TAKAHASHI Shun, YAMADA Noboru, YOSHIDA Takanori, DAIMARU Takuro, INOUE Takayoshi, KAWACHI Akiko, KAWAI Hiroki, MASUYAMA Yosuke, MATSUMIYA Hiroaki, MATSUMOTO Daishi

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN　14　(30)　Pi_17-Pi_26　2016
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/tastj.14.Pi_17 　

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A cooling system using oscillating heat pipe (OHP) has been developed for a balloon-borne astrophysics project GAPS (General Anti-Particle Spectrometer). Taking advantages of OHP, such as high conductivity, low-power, and suitability for spread heat source, OHP is planned to be used to cool the GAPS core detectors. OHP is a novel technique and it has never been utilized in practical use neither for a spacecraft nor for a balloon-craft, regardless of its many advantages. In these several years, we have investigated OHP's suitability for GAPS step by step. At first, we have succeeded in developing a scaleddown OHP model with a three-dimensional routing, which can operate in a wide temperature range around between 230 K and 300 K. We also succeeded in the first OHP flight demonstration with a prototype GAPS balloon experiment. Subsequently, we developed actual-sized OHP models with various routings. Numerical simulation models have been developed in parallel to further optimize the OHP design by understanding the OHP performance both macroscopically and microscopically. The design of the OHP check valve has been improved as well. This paper discusses the latest status of the GAPS-OHP development.
A Parametric Study of Mars Airplane Concept for Science Mission on Mars

FUJITA Koji, NAGAI Hiroki, OYAMA Akira

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN　14　(30)　Pk_83-Pk_88　2016
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/tastj.14.Pk_83 　

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Airplanes have been expected as a new platform for Mars exploration. This paper presents conceptual design results of a Mars airplane for various entry capsule diameters, payload mass, and flight range. The conceptual design method includes considerations of the deployment mechanism using hinges and aerodynamic characteristics at low Reynolds number. The results reveal a relation among total mass of the airplane, entry capsule size, payload mass, and flight range. When the total mass and entry capsule diameter are fixed, the flight range is expressed as a linear function of the payload mass with negative slope. When the entry capsule diameter and the payload mass are fixed, optimal total mass from the viewpoint of the flight range is found for each entry capsule diameter. Finally a specification of the airplane at the optimal total mass is shown. An airplane weighing 34.0 kg shows a maximum range of 370 km under the conditions of an aeroshell diameter of 3 m and a payload mass of 3 kg.
Effect of yaw-tilted hinge axis on deployment robustness of mars airplane Peer-reviewed

Koji Fujita, Hiroki Nagai, Akira Oyama

30th Congress of the International Council of the Aeronautical Sciences, ICAS 2016　2016
Visualization of hypersonic boundary layer transition on elliptic cone in high enthalpy shock tunnel with temperature-sensitive paint Peer-reviewed

Takehiro Nagayama, Hiroki Nagai, Hideyuki Tanno, Tomoyuki Komuro

54th AIAA Aerospace Sciences Meeting　2016
Development of Japanese mars airplane Peer-reviewed

Hiroki Nagai, Akira Oyama

Proceedings of the International Astronautical Congress, IAC　2016

ISSN： 0074-1795
Robust aerial deployment of mars airplane with tilted folding-axis Peer-reviewed

Koji Fujita, Hiroki Nagai, Akira Oyama

AIAA Atmospheric Flight Mechanics Conference　2016
国外における超音速&極超音速柔軟構造空力減速装置の研究開発の動向について

永井大樹

日本航空宇宙学会年会講演会講演集(CD-ROM)　47th　ROMBUNNO.1A2　2016
低レイノルズ数においてプロペラ後流の影響を受ける石井翼の空力性能

倉根翔, 永井大樹

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　48th-34th　ROMBUNNO.2A17　2016
将来深宇宙探査用二相流体メカニカルポンプループのシステム検討

坂元健一, 大丸拓郎, 永井大樹, SUNADA Eric, BHANDARI Pradeep, FURST Benjamin, CAPPUCCI Stefano

宇宙科学技術連合講演会講演集(CD-ROM)　60th　ROMBUNNO.2K14　2016

ISSN： 1884-1945
高高度飛行試験ミッションにおける火星探査飛行機の温度予測

小田泰之, 大丸拓郎, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　60th　ROMBUNNO.4C11　2016

ISSN： 1884-1945
複数蒸発器/凝縮器を有するループヒートパイプの熱輸送特性熱流体物性および周囲熱環境の影響

CHANG Xinyu, 長野方星, 岡崎峻, 小川博之, 永井大樹

日本伝熱シンポジウム講演論文集(CD-ROM)　53rd　ROMBUNNO.C121　2016

ISSN： 1346-1532
火星飛行機の高高度飛行試験結果の速報

大山聖, 永井大樹, 得竹浩, 藤田昂志, 安養寺正之, 豊田裕之, 宮澤優, 米本浩一, 岡本正人, 野々村拓, 元田敏和, 竹内伸介, 鎌田幸男, 大槻真嗣, 浅井圭介, 藤井孝藏

飛行機シンポジウム講演集(CD-ROM)　54th　ROMBUNNO.3J13　2016
圧力振動による自励振動ヒートパイプの内部流動様式の分類

吉田周平, 大丸拓郎, 永井大樹

混相流シンポジウム講演論文集(CD-ROM)　2016　ROMBUNNO.F111　2016
数値解析モデルによる平板型ヒートパイプ軌道上実験の検証

大丸拓郎, 永井大樹, 安藤麻紀子, 田中洸輔, 岡本篤, 杉田寛之

混相流シンポジウム講演論文集(CD-ROM)　2016　ROMBUNNO.F121　2016
セカンダリウィックがLoop Heat Pipeの熱輸送性能に与える影響の簡易数学モデルによる評価

安達拓矢, 大丸拓郎, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　60th　ROMBUNNO.2K05　2016

ISSN： 1884-1945
火星飛行機に最適化された主翼の空力特性に関する実験的評価

山原健太朗, 永井大樹, 金崎雅博

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　48th-34th　ROMBUNNO.2A08　2016
逆止弁付き自励振動ヒートパイプ軌道上実証試験における始動特性に関する考察

大丸拓郎, 永井大樹, 安藤麻紀子, 田中洸輔, 岡本篤, 杉田寛之

宇宙科学技術連合講演会講演集(CD-ROM)　60th　ROMBUNNO.2K08　2016

ISSN： 1884-1945
Present Status of Aerodynamic Heating Measurement Technique using Temperature-Sensitive Paint in HIEST Peer-reviewed

NAGAI Hiroki, NAGAYAMA Takehiro, TANNO Hideyuki, KOMURO Tomoyuki

The Proceedings of Mechanical Engineering Congress, Japan　2016　(0)　S1910206　2016
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecj.2016.S1910206 　
火星探査飛行機の高高度飛行試験計画（その4）

大山聖, 永井大樹, 得竹浩, 竹内伸介, 豊田裕之, 宮澤優, 大槻真嗣, 元田敏和, 岡本正人, 安養寺正之, 野々村拓, 鎌田幸男, 藤田昂志, 米本浩一, 浅井圭介, 藤井孝藏, 火星探査航空機ワーキンググループ, Oyama Akira, Nagai Hiroki, Tokutake Hiroshi, Takeuchi Shinsuke, Toyota Hiroyuki, Miyazawa Yu, Otsuki Masatsugu, Motoda Toshikazu, Okamoto Masato, Anyoji Masayuki, Nonomura Taku, Kamata Yukio, Fujita Koji, Yonemoto Koichi, Asai Keisuke, Fujii Kozo

大気球シンポジウム: 平成27年度 = Balloon Symposium: 2015　2015/11
Publisher: 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)

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大気球シンポジウム平成27年度（2015年11月5-6日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県著者人数: 16名ほか資料番号: SA6000044002レポート番号: isas15-sbs-002
数値解析による自励振動ヒートパイプ内の熱サイクルに関する研究

大丸拓郎, 吉田周平, 永井大樹

Thermophysical Properties　36th　69‐71　2015/10/19

ISSN： 0911-1743
逆止弁付き振動流型ヒートパイプの設計最適化を目指した熱輸送特性評価

田中洸輔, 安藤麻紀子, 岡本篤, 杉田寛之, 大丸拓郎, 永井大樹

Thermophysical Properties　36th　66‐68　2015/10/19

ISSN： 0911-1743
可視化によるチェックバルブ付き自励振動ヒートパイプの循環流に関する考察

吉田周平, 大丸拓郎, 永井大樹, LIU Tianshu, 沼田大樹, 浅井圭介

Thermophysical Properties　36th　84‐86　2015/10/19

ISSN： 0911-1743
感温塗料計測技術の高温衝撃風洞HIESTへの適用

永井大樹, 長山剛大, 丹野英幸, 小室智幸

Thermophysical Properties　36th　63‐65　2015/10/19

ISSN： 0911-1743
Effect of Hinge Axis Tilting on Aerial Deployment of Mars Airplane

藤田昂志, 永井大樹, 大山聖

宇宙科学技術連合講演会講演集　59　6p　2015/10/07
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
Thermal Design of DESTINY Using Advanced Thermal Control Technology

岡崎峻, 長野方星, 永井大樹

宇宙科学技術連合講演会講演集　59　6p　2015/10/07
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
Effects of Check Valves on Operating Characteristics of Oscillating Heat Pipes

大丸拓郎, 吉田周平, 永井大樹

宇宙科学技術連合講演会講演集　59　5p　2015/10/07
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
感温塗料を用いた高温衝撃風洞におけるHIFiRE模型の境界層遷移可視化

長山剛大, 永井大樹, 丹野英幸, 小室智幸

日本機械学会年次大会講演論文集(CD-ROM)　2015　ROMBUNNO.S1910301　2015/09/12
Aerodynamic evaluation of a capsule shaped projectile during free flight testing with ballistic range Peer-reviewed

Akiho Ishida, Hiroki Nagai, Hideyuki Tanno, Tomoyuki Komuro

53rd AIAA Aerospace Sciences Meeting　2015

DOI： 10.2514/6.2015-0244 　
低レイノルズ数におけるプロペラ後流の影響を受けた三次元翼空力特性

永井大樹, 渡辺高太郎

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　47th-33rd　ROMBUNNO.2D08　2015
マルチエバポレータ型ループヒートパイプの内部可視化に基づく熱流動モデルの提案

木澤雅文, 長野方星, 岡崎峻, 小川博之, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　59th　ROMBUNNO.3M15　2015

ISSN： 1884-1945
火星飛行機の空中展開に対するヒンジ軸傾斜の効果

藤田昂志, 永井大樹, 大山聖

宇宙科学技術連合講演会講演集(CD-ROM)　59th　ROMBUNNO.1E07　2015

ISSN： 1884-1945
Loop Heat Pipeの熱輸送向上を目指したセカンダリウィック最適形状の提案

安達拓矢, 竹谷雅彦, 大丸拓郎, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　59th　ROMBUNNO.3M14　2015

ISSN： 1884-1945
自励振動ヒートパイプの動作特性における逆止弁の影響

大丸拓郎, 吉田周平, 永井大樹, 岡本篤, 安藤麻紀子, 田中洸輔, 杉田寛之

宇宙科学技術連合講演会講演集(CD-ROM)　59th　ROMBUNNO.3M12　2015

ISSN： 1884-1945
先進熱制御デバイスを用いたDESTINY熱設計

岡崎峻, 長野方星, 永井大樹, 小川博之, 川勝康弘

宇宙科学技術連合講演会講演集(CD-ROM)　59th　ROMBUNNO.2G06　2015

ISSN： 1884-1945
S1910301 Visualization of Boundary Layer Transition on HIFiRE Model in High-Enthalpy Shock Tunnel Using Temperature-Sensitive Paint

NAGAYAMA Takehiro, NAGAI Hiroki, TANNO Hideyuki, KOMURO Tomoyuki

The Proceedings of Mechanical Engineering Congress, Japan　2015　(0)　_S1910301--_S1910301-　2015
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecj.2015._S1910301- 　

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A visualization experiment of hypersonic boundary layer transition by Temperature-Sensitive Paint (TSP) was performed. The test facility was High-Enthalpy Shock Tunnel (HIEST) at Japan Aerospace Exploration Agency (JAXA) Kakuda Space Center. An elliptic cone model with a 2:1 aspect ratio, which is a full-scale model of HIFiRE-5, was used as the test model. This study visualized the hypersonic boundary layer transition on the side of the test model. TSP was excited by a Blue-LED and the luminescence from TSP was detected by a high-speed camera. Temperature distribution on the side of the test model was obtained by TSP. Moreover, boundary layer transition along the centerline of the model and in approximately halfway between the centerline and leading edge were visualized. The trend of temperature rise along the centerline is same in TSP and thermocouples, which is inserted on the centerline of the test model.
高温環境における非破壊検査の現状と展望次世代高温環境センサの展望と産業応用

高木敏行, 庄司一夫, 和佐泰宏, 米津豊作, 冨田健夫, 風岡学, 永井大樹, 町島祐一, 内一哲哉

非破壊検査　63　(12)　604-611　2014/12/01
Publisher: 日本非破壊検査協会
ISSN： 0367-5866
Aerodynamic Challenges to Realize Mars Airplane

永井大樹, 安養寺正之, 野々村拓

宇宙科学技術連合講演会講演集　58　6p　2014/11/12
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
Conceptual Design of a Mars Airplane for a Technological Demonstrator of a Mars Lander

藤田昂志, 永井大樹, 大山聖

宇宙科学技術連合講演会講演集　58　6p　2014/11/12
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
DESTINY : Understanding of Martian dust transport mechanisms

小郷原一智, 大山聖, 永井大樹

宇宙科学技術連合講演会講演集　58　4p　2014/11/12
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
A Consideration of Startup Behavior of Oscillating Heat Pipes

大丸拓郎, 吉田周平, 永井大樹

宇宙科学技術連合講演会講演集　58　5p　2014/11/12
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
The Effects of Secondary Wicks Configuration on the Performance of Loop Heat Pipe

竹谷政彦, 永井大樹

宇宙科学技術連合講演会講演集　58　6p　2014/11/12
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
火星探査飛行機の高々度飛行試験の進捗報告

大山聖, 永井大樹, 得竹浩, 竹内伸介, 豊田裕之, 宮澤優, 大槻真嗣, 元田敏和, 岡本正人, 安養寺正之, 野々村拓, 鎌田幸男, 藤田昴志, 平栗弘貴, 佐々木岳, 米本浩一, 浅井圭介, 藤井孝藏, 火星探査航空機ワーキンググループ, Oyama Akira, Nagai Hiroki, Tokutake Hiroshi, Takeuchi Shinsuke, Toyota Hiroyuki, Miyazawa Yu, Otsuki Masatsugu, Motoda Toshikazu, Okamoto Masato, Anyoji Masayuki, Nonomura Taku, Kamata Yukio, Fujita Koji, Hiraguri Hirotaka, Sasaki Gaku, Yonemoto Koichi, Asai Keisuke, Fujii Kozo

大気球シンポジウム: 平成26年度 = Balloon Symposium: 2014　2014/11
Publisher: 宇宙航空研究開発機構宇宙科学研究所（JAXA)(ISAS)

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大気球シンポジウム平成26年度（2014年11月6-7日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県著者人数: 18名資料番号: SA6000021006レポート番号: isas14-sbs-006
南極周回気球による宇宙線反粒子探索計画 GAPS

福家英之, 野々村拓, 小川博之, 岡崎峻, 田中結, 吉田哲也, 安部拓洋, 井上剛良, 松宮宏明, 依田悠太郎, 大丸拓郎, 永井大樹, 河内明子, 増山陽介, 清水憲政, 高橋俊, 小池貴久, 宮崎芳郎, 佐藤大輔, 高橋克征, 山田昇, 吉田貴則, 荒牧嗣夫, Gahbauer F., Hailey C. J., Madden N., 森嘉野, Perez K., Boggs S., Hoberman J., Fuke Hideyuki, Nonomura Taku, Ogawa Hiroyuki, Okazaki Shun, Tanaka Yui, Yoshida Tetsuya, Abe Takumi, Inoue Takayoshi, Matsumiya Hiroaki, Yoda Yutaro, Daimaru Takuro, Nagai Hiroki, Kawachi Akiko, Masuyama Yousuke, Shimizu Kensei, Takahashi Shun, Koike Takahisa, Miyazaki Yoshio, Sato Daisuke, Takahashi Katsumasa, Yamada Noboru, Yoshida Takanori, Aramaki Tsuguo, Gahbauer F., Hailey C. J., Madden N., Mori Kaya, Perez K., Boggs S., Hoberman J.

大気球シンポジウム: 平成26年度 = Balloon Symposium: 2014　2014/11
Publisher: 宇宙航空研究開発機構宇宙科学研究所（JAXA)(ISAS)

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大気球シンポジウム平成26年度（2014年11月6-7日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県著者人数: 37名資料番号: SA6000021002レポート番号: isas14-sbs-002
LPSO型Mg合金を用いた火星探査航空機用軽量翼構造の試作

竹内伸介, 佐藤英一, 大山聖, 永井大樹

日本学術会議材料工学連合講演会講演論文集　58th　122-123　2014/10/27
カプセル形状模型の自由飛行計測における空力特性評価

石田照歩, 永井大樹, 丹野英幸, 小室智幸

日本機械学会年次大会講演論文集(CD-ROM)　2014　ROMBUNNO.S1910203　2014/09/06
Report of the 46th Fluid Dynamics Conference and the 32nd Aerospace Numerical Simulation Symposium

NAGAI Hiroki

Aeronautical and Space Sciences Japan　62　(11)　380-381　2014
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.14822/kjsass.62.11_380 　

ISSN： 0021-4663
Application of PSP Measurement to Low-speed Flow

YORITA Daisuke, ASAI Keisuke, NAGAI Hiroki, Numata Daiju

Journal of the Visualization Society of Japan　34　(132)　16-21　2014
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.34.132_16 　

ISSN： 0916-4731

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Pressure sensitive paint (PSP) is an optical technique to measure surface pressure. PSP is now widely used in various wind-tunnel tests, however application to low-speed flow is still one of the most difficult challenges for PSP. Pressure change in low-speed test is quite small, although PSP measurement has various error sources. It is important to understand key-point of low-speed PSP application and minimize the measurement errors. In this study, recent development of PSP techniques for low-speed tests, both steady and unsteady pressure measurement, are discussed.
次世代高温環境センサの展望と産業応用 Invited

高木敏行, 庄司一夫, 和佐泰宏, 米津豊作, 冨田健夫, 風岡学, 永井大樹, 町島祐一, 内一哲哉

非破壊検査　63　(12)　1-8　2014
Development of temperature-sensitive paint with high performance and responsivity for aerodynamic heating measurement Peer-reviewed

Takehito Horagiri, Hiroki Nagai

52nd Aerospace Sciences Meeting　2014
Propeller slipstream interference with wing aerodynamic characteristics of mars airplane at low reynolds number Peer-reviewed

Fumiyasu Makino, Hiroki Nagai

52nd Aerospace Sciences Meeting　2014
Numerical study of wind-tunnel acoustic resonance induced by two-dimensional airfoil flow at low reynolds number Peer-reviewed

Tomoaki Ikeda, Takashi Atobe, Yasufumi Konishi, Hiroki Nagai, Keisuke Asai

29th Congress of the International Council of the Aeronautical Sciences, ICAS 2014　2014
Propeller slipstream interference with wing aerodynamic characteristics of mars airplane at low reynolds number Peer-reviewed

Fumiyasu Makino, Hiroki Nagai

52nd AIAA Aerospace Sciences Meeting - AIAA Science and Technology Forum and Exposition, SciTech 2014　2014
Development of temperature-sensitive paint with high performance and responsivity for aerodynamic heating measurement Peer-reviewed

Takehito Horagiri, Hiroki Nagai

52nd AIAA Aerospace Sciences Meeting - AIAA Science and Technology Forum and Exposition, SciTech 2014　2014
Numerical analysis for an aerial deployment motion of a folded-wing airplane Peer-reviewed

Koji Fujita, Toshikazu Motoda, Hiroki Nagai

AIAA Atmospheric Flight Mechanics Conference　2014

DOI： 10.2514/6.2014-0383 　
プロペラ後流が主翼に及ぼす影響―表面流れ場の観測―

永井大樹, 牧野文康

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　46th-32nd　ROMBUNNO.1D09　2014
自励振動ヒートパイプの始動特性における初期気液分布の影響

大丸拓郎, 吉田周平, 永井大樹, 岡本篤, 安藤麻紀子, 杉田寛之

混相流シンポジウム講演論文集(CD-ROM)　2014　ROMBUNNO.B113　2014
DESTINYミッションモジュール熱設計の最適化

岡崎峻, 吉田周平, 押山大佑, 大丸拓郎, 永井大樹, 小川博之, 川勝康弘

宇宙科学技術連合講演会講演集(CD-ROM)　58th　ROMBUNNO.1B19　2014

ISSN： 1884-1945
遷音速自由飛行試験におけるHTV‐Rカプセル模型の運動のモデル化の検討

石田照歩, 永井大樹, 丹野英幸, 小室智幸

宇宙科学技術連合講演会講演集(CD-ROM)　58th　ROMBUNNO.2L07　2014

ISSN： 1884-1945
DESTINY応用:火星気象衛星と火星航空機によるダスト輸送メカニズムの解明ミッション

小郷原一智, 大山聖, 永井大樹, 得竹浩

宇宙科学技術連合講演会講演集(CD-ROM)　58th　ROMBUNNO.2B08　2014

ISSN： 1884-1945
火星着陸探査技術実証機への搭載を目指した火星飛行機の概念設計

藤田昂志, 永井大樹, 大山聖

宇宙科学技術連合講演会講演集(CD-ROM)　58th　ROMBUNNO.1B07　2014

ISSN： 1884-1945
バリスティックレンジによるカプセル形状模型の自由飛行試験

丹野英幸, 小室智幸, 石田照歩, 永井大樹

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　46th-32nd　ROMBUNNO.2A12　2014
セカンダリウィックの形状がループヒートパイプの動作に与える影響

竹谷政彦, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　58th　ROMBUNNO.2E07　2014

ISSN： 1884-1945
火星探査航空機WGにおける空力研究のこれまでの成果と現状

永井大樹, 安養寺正之, 野々村拓, 近藤勝俊, 大山聖, 岡本正人, 佐々木岳, 松本剛明, 米本浩一, 金崎雅博, 砂田茂, 米澤宏一, 小池勝, 藤田昂志, 浅井圭介, 藤井孝藏

宇宙科学技術連合講演会講演集(CD-ROM)　58th　ROMBUNNO.1B01　2014

ISSN： 1884-1945
火星探査航空機の全機空力特性に関する風洞実験および数値解析

安養寺正之, 岡本正人, 藤岡直也, 野々村拓, 永井大樹, 大山聖, 藤井孝藏, 山本誠

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　46th-32nd　ROMBUNNO.1D11　2014
微小重力環境下でのマルチエバポレータ型ループヒートパイプの熱流動特性

長野方星, 松田雄太, 岡崎駿, 小川博之, 永井大樹

混相流シンポジウム講演論文集(CD-ROM)　2014　ROMBUNNO.B123　2014
マルチエバポレータ型ループヒートパイプの内部流動特性に関する研究(微小重力環境下での蒸発器及び凝縮器の可視化)

松田雄太, 長野方星, 岡崎峻, 小川博之, 永井大樹

日本伝熱シンポジウム講演論文集(CD-ROM)　51st　ROMBUNNO.G324　2014

ISSN： 1346-1532
火星探査飛行機用推進装置の研究・開発

米澤宏一, 砂田茂, 大槻真嗣, 安養寺正之, 永井大樹, 浅井圭介, 岡本正人

宇宙科学技術連合講演会講演集(CD-ROM)　58th　ROMBUNNO.1B02　2014

ISSN： 1884-1945
ステンレスウイックを用いたループヒートパイプの熱輸送性能評価

岡崎峻, 永井大樹, 長野方星, 小川博之

日本伝熱シンポジウム講演論文集(CD-ROM)　51st　ROMBUNNO.G323　2014

ISSN： 1346-1532
自励振動ヒートパイプの振動形態に関する一考察

吉田周平, 大丸拓郎, 永井大樹

混相流シンポジウム講演論文集(CD-ROM)　2014　ROMBUNNO.B111　2014
自励振動ヒートパイプのスタートアップに関する一考察

大丸拓郎, 吉田周平, 永井大樹, 岡本篤, 安藤麻紀子, 杉田寛之

宇宙科学技術連合講演会講演集(CD-ROM)　58th　ROMBUNNO.2E01　2014

ISSN： 1884-1945
火星探査航空機実現のための空力課題とその現状

永井大樹

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　46th-32nd　ROMBUNNO.1D12　2014
逆止弁付自励振動ヒートパイプの内部流動モデル構築

大丸拓郎, 吉田周平, 永井大樹, 岡本篤, 安藤麻紀子, 杉田寛之

日本機械学会熱工学コンファレンス講演論文集(CD-ROM)　2014　ROMBUNNO.F224　2014
PSPの低速流れへの応用

依田大輔, 浅井圭介, 永井大樹, 沼田大樹

可視化情報学会誌　34　(132)　16-21,1(2)　2014/01/01

ISSN： 0916-4731
F224 Mathematical Modeling of Oscillating Heat Pipes with Check Valves

Daimaru Takurou, Yoshida Shuhei, Nagai Hiroki, Okamoto Atsushi, Ando Makiko, Sugita Hiroyuki

The Proceedings of the Thermal Engineering Conference　2014　(0)　_F224-1_-_F224-2_　2014
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmeted.2014._F224-1_ 　

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A mathematical model of Oscillating Heat Pipes (OHPs) with check valves has been constructed. The mathematical model was a one-dimensional slug flow model. Movement of liquid slugs was governed by pressure differences among vapor plugs and by pressure drops in the tubes. Check valves were reproduced by change of liquid slug's momentum. As a result, check valves caused the circulation flow in OHP.
S1910203 The Aerodynamic Characteristics Evaluation of Capsule Model in Free Flight Testing

Ishida Akiho, Nagai Hiroki, Tanno Hideyuki, Komuro Tomoyuki

The Proceedings of Mechanical Engineering Congress, Japan　2014　(0)　_S1910203--_S1910203-　2014
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecj.2014._S1910203- 　

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The HTV Return Vehicle (HRV) is a re-entry capsule with a blunt body that is being considered by Japan Aerospace Exploration Agency (JAXA) as a new space vehicle. The aerodynamic characteristics must be clarified for the HRV design and trajectory because of the capsule's dynamic instability at transonic. A single degree-of-freedom free-rotation test method in a wind tunnel was employed in a previous study. In this study, free flight tests of a re-entry lifting capsule were conducted in the JAXA HEK-G Ballistic Range. The motion in free flight was measured by four acceleration sensors for the pitching and yawing directions. The angular acceleration data from the tests under the same conditions are compared and discussed.
Effects of Secondary Wick on Thermal Characteristics of Loop Heat Pipe

竹谷政彦, 永井大樹

宇宙科学技術連合講演会講演集　57　6p　2013/10/09
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
Preliminary Design and Thermal Analysis of Miniature Mars Airplane Thermal Control System

大丸拓郎, 永井大樹

宇宙科学技術連合講演会講演集　57　6p　2013/10/09
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
Thermal Analysis of Mars Airplane Balloon Experiment-1 (MABE1)

永井大樹, 大丸拓郎

宇宙科学技術連合講演会講演集　57　5p　2013/10/09
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
Development of Temperature-Sensitive Paint with High Performance and Responsibility for Aerodynamic Heating Measurement

洞桐健人, 永井大樹

可視化情報学会誌　33　(Suppl.1)　493‐498　2013/07/01

ISSN： 0916-4731
極超音速流れにおける30°ランプ周りの衝撃波干渉に関する数値解析:スパン幅が流れ場構造に与える影響

倉本健史, 武藤大貴, 坪井伸幸, 永井大樹, 浅井圭介

衝撃波シンポジウム講演論文集　2012　335-338　2013/03/13
Characteristics of low-Reynolds number airfoils in a mars wind tunnel Peer-reviewed

Hiroki Nagai, Keisuke Asai, Daiju Numata, Tetsuya Suwa, Masayuki Anyoji

51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2013　2013
Development of ultrafast-response anodized-aluminum pressure-sensitive paints Peer-reviewed

Shota Fujii, Daiju Numata, Hiroki Nagai, Keisuke Asai

51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2013　2013
Preliminary design and thermal analysis of a miniature mars airplane thermal control system Peer-reviewed

Takurou Daimaru, Hiroki Nagai

43rd International Conference on Environmental Systems　2013
Operational characteristics of the Oscillating Heat Pipe with Non-Condensable Gas Peer-reviewed

Takurou Daimaru, Hiroki Nagai

43rd International Conference on Environmental Systems　2013
ループヒートパイプの熱特性におけるセカンダリウィックの影響

竹谷政彦, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　57th　ROMBUNNO.2I01　2013

ISSN： 1884-1945
低レイノルズ数における音響フィードバック現象解明を目指したNACA0012翼型の後流計測

永井大樹, 酒井宣明, 浅井圭介, 池田友明, 跡部隆

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　45th-2013　ROMBUNNO.2D12　2013
大気球を利用した火星探査航空機の高高度飛行実証試験

永井大樹, 大山聖, 得竹浩, 竹内伸介, 豊田裕之, 高橋優, 大槻真嗣, 安養寺正之, 岡本正人, 元田敏和, 米本浩一, 浅井圭介, 藤井孝藏

飛行機シンポジウム講演集(CD-ROM)　51st　ROMBUNNO.3D04　2013
セカンダリウィック付ループヒートパイプの過渡特性解析

眞籠耕平, 竹谷政彦, 永井大樹

日本伝熱シンポジウム講演論文集(CD-ROM)　50th　ROMBUNNO.G231　2013

ISSN： 1346-1532
大気球を利用した火星探査航空機の高高度飛行実証機に関する熱的検討

永井大樹, 大丸拓郎

宇宙科学技術連合講演会講演集(CD-ROM)　57th　ROMBUNNO.3C01　2013

ISSN： 1884-1945
自励振動ヒートパイプにおける非凝縮ガスの影響

大丸拓郎, 永井大樹

日本伝熱シンポジウム講演論文集(CD-ROM)　50th　ROMBUNNO.SP36　2013

ISSN： 1346-1532
火星大気を飛行する航空機の第一次熱設計

大丸拓郎, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　57th　ROMBUNNO.2I10　2013

ISSN： 1884-1945
火星着陸探査機の概念設計ベースライン

藤田和央, 石上玄也, 尾川順子, 畠中龍太, 佐藤毅彦, 山岸明彦, 宮本英昭, 鈴木俊之, 山田和彦, 松本秀一, 豊田裕之, 中塚潤一, 竹内央, 大山聖, 永井大樹, 久保田孝

宇宙科学技術連合講演会講演集(CD-ROM)　57th　ROMBUNNO.2C09　2013

ISSN： 1884-1945
低レイノルズ数翼の空力特性に対する圧縮性の効果

諏訪哲也, 吉野貴保子, 沼田大樹, 永井大樹, 浅井圭介

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　45th-2013　ROMBUNNO.2D03　2013
低レイノルズ数領域でのプロペラ後流における主翼の空力性能

永井大樹, 牧野文康

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　45th-2013　ROMBUNNO.2D09　2013
低Re数領域の平面形空力特性に対するRe数効果

安養寺正之, 野々村拓, 大山聖, 藤井孝藏, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　57th　ROMBUNNO.3C05　2013

ISSN： 1884-1945
低圧における感圧塗料の周波数応答特性

佐々木大介, 沼田大樹, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(13-002(CD-ROM))　ROMBUNNO.P10　2013

ISSN： 1349-113X
陽極酸化アルミ皮膜型感圧塗料の細孔構造制御と時間応答性評価

藤井祥太, 沼田大樹, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(13-002(CD-ROM))　ROMBUNNO.P11　2013

ISSN： 1349-113X
極超音速流れにおける30°ランプ周りの衝撃波干渉の数値解析:流れ場の非定常性について

倉本健史, 武藤大貴, 坪井伸幸, 永井大樹, 浅井圭介

日本機械学会流体工学部門講演会講演論文集(CD-ROM)　91st　ROMBUNNO.0901　2013

ISSN： 1348-2882
フォスファーを用いた高温領域における温度分布計測技術の開発

石田照歩, 西潟一樹, 永井大樹

宇宙航空研究開発機構特別資料 JAXA-SP-　(13-002(CD-ROM))　ROMBUNNO.P04　2013

ISSN： 1349-113X
動的風洞試験への適用のための複合感圧塗料開発

原達矢, 沼田大樹, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(13-002(CD-ROM))　ROMBUNNO.P03　2013

ISSN： 1349-113X
感温塗料の応答性評価

洞桐健人, 永井大樹

宇宙航空研究開発機構特別資料 JAXA-SP-　(13-002(CD-ROM))　ROMBUNNO.P13　2013

ISSN： 1349-113X
0901 Numerical Study of Shock Interaction over Compression Corner with 30 deg. in Hypersonic Flow : Unsteady Characteristics of Flow Field.

KURAMOTO Takeshi, MUTOH Daiki, TSUBOI Nobuyuki, NAGAI Hiroki, ASAI Keisuke

The Proceedings of the Fluids engineering conference　2013　(0)　_0901-01_-_0901-02_　2013
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmefed.2013._0901-01_ 　

ISSN： 1348-0251

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In hypersonic flow, the shock interactions cause high surface heat flux. Furthermore, the unsteady vortices are generated over a compression corner. Present study investigates the relation between the distribution of the surface heat flux and the unsteady vortices. The flow field over the compression corner with 30 deg. is calculated by the three-dimensional numerical simulations. The heat flux distributions on the model surface show some unsteady longitudinal streaks, because the longitudinal vortices merge and separate cyclically.
Development of Temperature-Sensitive Paint with High Performance and Responsibility for Aerodynamic Heating Measurement

洞桐健人, 永井大樹

可視化情報学会誌 = ournal of the Visualization Society of Japan　33　(1)　493-498　2013
Publisher: 可視化情報学会
ISSN： 0916-4731
ガスタービンに関連するCFD技術の最前線実験・計測最新技術

浅井圭介, 永井大樹, 沼田大樹

日本ガスタービン学会誌　40　(6)　304-310,257(6)　2012/11/20

ISSN： 0387-4168
Advance in Experiment and measurement Techniques

ASAI Keisuke, NAGAI Hiroki, NUMATA Daiju

Journal of the Gas Turbine Society of Japan　40　(6)　304-310,図巻頭1p　2012/11
Publisher: Gas Turbine Society of Japan
ISSN： 0387-4168
機能性分子センサによる熱流体計測法

永井大樹

機械の研究　64　(11)　929-935　2012/11
Publisher: 養賢堂
ISSN： 0368-5713
機能性分子センサによる熱流体計測法

永井大樹

機械の研究　64　(11)　929-935　2012/11/01

ISSN： 0368-5713
Temperature Distribution Measurement Technique for High-Temperature using Phosphor

永井大樹, 澤村亮輔, 浅井圭介

可視化情報学会誌　32　(Suppl.2)　241‐242　2012/09/15

ISSN： 0916-4731
サッカーボール表面圧力場のPSP計測

瀬尾和哉, 依田大輔, 永井大樹, 浅井圭介, 浅井武, 伊藤慎一郎

日本機械学会年次大会講演論文集(CD-ROM)　2012　ROMBUNNO.J052011　2012/09/08
自励振動ヒートパイプにおける非凝縮ガスの影響

大丸拓郎, 永井大樹

日本混相流学会年会講演会講演論文集　2012　236-237　2012/08
Aerodynamic Behavior of a Soccer Ball

瀬尾和哉, 依田大輔, 永井大樹, 浅井圭介, 浅井武, 伊藤慎一郎

可視化情報学会誌　32　(Suppl.1)　345‐348　2012/07/01

ISSN： 0916-4731
Response Time Evaluation of Temperature-Sensitive Paint

洞桐健人, 西潟一樹, 永井大樹

可視化情報学会誌　32　(Suppl.1)　285‐288-288　2012/07/01
Publisher: 可視化情報学会
ISSN： 0916-4731
Development of Back Surface TSP Measurement Technique for Shock Interaction Aerodynamic Heating in High Enthalpy Flow

西潟一樹, 永井大樹, 浅井圭介

可視化情報学会誌　32　(Suppl.1)　289‐292-292　2012/07/01
Publisher: 可視化情報学会
ISSN： 0916-4731
Analysis of Shock-Wave Structures in a Supersonic Biplane by Focusing Schlieren Technique

HAGIWARA Masumi, NAGAI Hiroki, NUMATA Daiju, ASAI Keisuke

日本航空宇宙学会論文集 = Journal of the Japan Society for Aeronautical and Space Sciences　60　(3)　142-147　2012/06/05

ISSN： 1344-6460
Report of VSJ Culture Forum in Sendai : Scientific Visualization Explores Invisible Universe

ASAI Keisuke, NAGAI Hiroki

可視化情報学会誌 = Journal of the Visualization Society of Japan　32　(125)　87-88　2012/04/01

ISSN： 0916-4731
極超音速流れにおける30°ランプ周りの流れ場の数値解析:平板幅の影響

倉本健史, 武藤大貴, 坪井伸幸, 永井大樹, 浅井圭介

日本機械学会九州支部講演論文集　65th　289-290　2012/03/16
非定常衝撃波現象への適用を目指した超高速応答型感圧塗料の開発

藤井祥太, 沼田大樹, 永井大樹, 浅井圭介

衝撃波シンポジウム講演論文集　2011　311-312　2012/03/07
‘Wind Tunnel’ feature article

MORITA Kiyoshi, NAGAI Hiroki

Journal of the Visualization Society of Japan　32　(124)　2-2　2012
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.32.124_2 　

ISSN： 0916-4731
Planetary Locomotion : New Options for Exploration on Planets

ASAI Keisuke, NAGAI Hiroki

Aeronautical and Space Sciences Japan　60　(11)　421-426　2012
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.14822/kjsass.60.11_421 　

ISSN： 0021-4663
Characterization of frequency response of pressure-sensitive paints Peer-reviewed

Tamao Sugimoto, Sakiko Kitashima, Daiju Numata, Hiroki Nagai, Keisuke Asai

50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition　2012
Conceptual design of a miniature, propeller-driven airplane for mars Peer-reviewed

Koji Fujita, Hiroki Nagai, Keisuke Asai

50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition　2012

DOI： 10.2514/6.2012-847 　
Compressibility effects on airfoil aerodynamics at low Reynolds number Peer-reviewed

Tetsuya Suwa, Kei Nose, Daiju Numata, Hiroki Nagai, Keisuke Asai

30th AIAA Applied Aerodynamics Conference 2012　1571-1583　2012

DOI： 10.2514/6.2012-3029 　
翼面上の2次元摩擦応力分布の光学的測定法

中村勘太, 依田大輔, 沼田大樹, 永井大樹, 浅井圭介

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　44th-2012　ROMBUNNO.2D13　2012
低レイノルズ数翼に生じる音響フィードバックの実験的研究

野瀬慶, 永井大樹, 浅井圭介, 池田友明, 跡部隆

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　44th-2012　ROMBUNNO.2E19　2012
火星飛行機のプロペラ後流の流れが翼性能に及ぼす影響の調査

牧野文康, 永井大樹, 浅井圭介

宇宙科学技術連合講演会講演集(CD-ROM)　56th　ROMBUNNO.2E07　2012

ISSN： 1884-1945
セカンダリウィック付ループヒートパイプの過渡特性解析

眞籠耕平, 竹谷政彦, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　56th　ROMBUNNO.1N02　2012

ISSN： 1884-1945
自励振動ヒートパイプにおける非凝縮ガスの影響

大丸拓郎, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　56th　ROMBUNNO.1N01　2012

ISSN： 1884-1945
火星飛行機の全機特性

安養寺正之, 永井大樹, 大山聖, 藤井孝藏

宇宙科学技術連合講演会講演集(CD-ROM)　56th　ROMBUNNO.2E03　2012

ISSN： 1884-1945
火星飛行機の空中翼展開時における動的挙動の計測と評価

藤田昂志, 永井大樹, 浅井圭介

宇宙科学技術連合講演会講演集(CD-ROM)　56th　ROMBUNNO.2E05　2012

ISSN： 1884-1945
PTFE多孔体を用いた宇宙用小型ループヒートパイプの性能評価

西川原理仁, 長野方星, 岡崎峻, 小川博之, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　56th　ROMBUNNO.1N03　2012

ISSN： 1884-1945
火星探査航空機にむけた高高度飛行試験の飛行経路検討

元田敏和, 大山聖, 永井大樹, 得竹浩

宇宙科学技術連合講演会講演集(CD-ROM)　56th　ROMBUNNO.2E02　2012

ISSN： 1884-1945
MELOS1にむけた火星飛行機の高高度飛行試験計画

大山聖, 永井大樹, 得竹浩, 竹内伸介, 豊田裕之, 藤田昂志, 安養寺正之, 元田敏和, 米本浩一, 浅井圭介, 藤井孝藏

宇宙科学技術連合講演会講演集(CD-ROM)　56th　ROMBUNNO.2E01　2012

ISSN： 1884-1945
火星探査航空機の地上における高高度飛行実証試験

永井大樹, 大山聖, 得竹浩, 竹内伸介, 安養寺正之

飛行機シンポジウム講演集(CD-ROM)　50th　ROMBUNNO.1C09　2012
極超音速流れにおける30°ランプ周りの衝撃波干渉に関する数値解析:熱流束に与える影響

倉本健史, 坪井伸幸, 永井大樹, 浅井圭介

日本航空宇宙学会西部支部講演会講演集(CD-ROM)　2012　ROMBUNNO.JSASS-2012-S010　2012
非定常感圧塗料計測の動的風洞試験への適用

原達矢, 阿部弘之, 依田大輔, 沼田大樹, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(12-001(CD-ROM))　ROMBUNNO.P08　2012

ISSN： 1349-113X
PTFEウィックを用いたマルチエバポレータ/コンデンサ型ループヒートパイプの動作特性

奥谷翔, 長野方星, 岡崎俊, 小川博之, 永井大樹

日本伝熱シンポジウム講演論文集(CD-ROM)　49th　ROMBUNNO.E224　2012

ISSN： 1346-1532
高速非定常流体現象解明のための超高速応答型感圧塗料の開発

藤井祥太, 沼田大樹, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(12-001(CD-ROM))　ROMBUNNO.P16　2012

ISSN： 1349-113X
812 Three-Dimensional Numerical Study of Flow around Compression Corner with 30 Degrees in Hypersonic Flow:Effects of Plate Width

KURAMOTO Takeshi, MUTOH Daiki, TSUBOI Nobuyuki, NAGAI Hiroki, ASAI Keisuke

The Proceedings of Conference of Kyushu Branch　2012　(0)　289-290　2012
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmekyushu.2012.65.289 　
J052011 PSP measurement of a Soccer Ball

SEO Kazuya, YORITA Daisuke, NAGAI Hiroki, ASAI Keisuke, ASAI Takeshi, ITO Shinichiro

The Proceedings of Mechanical Engineering Congress, Japan　2012　(0)　_J052011-1-_J052011-3　2012
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecj.2012._J052011-1 　

More details Close

PSP measurement of a non-spinning soccer ball has been carried out. It is found that the seam of the ball is the trigger for initiating low pressure. The depth of the seam on the ball was measured. It is found that the depth of the seam on the ball affects the critical Reynolds number. The deeper the depth is designed, the smaller the critical Reynolds number is achieved.
Aerodynamic Behavior of a Soccer Ball

瀬尾和哉, 依田大輔, 永井大樹

可視化情報学会誌 = ournal of the Visualization Society of Japan　32　(1)　345-348　2012
Publisher: 可視化情報学会
ISSN： 0916-4731
極超音速流れにおける30°ランプ周りの衝撃波干渉に関する数値解析 : 熱流束に与える影響

倉本健史, 坪井伸幸, 永井大樹

日本航空宇宙学会西部支部講演会講演集　4p　2012
Publisher: [日本航空宇宙学会西部支部]
バルク超伝導体を利用した小型磁場発生装置の開発

安部隆士, 山田和彦, 新倉脩平, 服部盛正, 永井大樹, 淡路智

東北大学金属材料研究所強磁場超伝導材料研究センター年次報告　2010　177-180　2011/08
ループヒートパイプの作動特性に対する重力加速度の影響

永井大樹, 玉村大道, 真籠耕平, 長野方星, 小川博之

日本混相流学会年会講演会講演論文集　2011　126-127　2011/08
Unsteady Aerodynamic Force Measurement Using Pressure-Sensitive Paint

依田大輔, 山崎真一, 沼田大樹, 永井大樹, 浅井圭介

可視化情報学会誌　31　(Suppl.1)　277-280　2011/07/01
Publisher: 可視化情報学会
ISSN： 0916-4731
High-accuracy Calculation of Aerodynamic Heating using Temperature-Sensitive Paint

西潟一樹, 澤村亮輔, 永井大樹, 浅井圭介

可視化情報学会誌　31　(Suppl.1)　269-272　2011/07/01

ISSN： 0916-4731
Development for Temperature-Sensitive Paint for Cryogenic Cavitation Test

藤井祥太, 新井山一樹, 永井大樹, 浅井圭介

可視化情報学会誌　31　(Suppl.1)　273-276　2011/07/01

ISSN： 0916-4731
Development of a small He II cryostat with optical windows for a microgravity experiment

N. Kimura, S. Takada, S. Gotoh, H. Kawamata, M. Iida, M. Murakami, H. Nagai, M. Mamiya

CRYOGENICS　51　(1)　74-78　2011/01

DOI： 10.1016/j.cryogenics.2010.10.008 　

ISSN： 0011-2275
Supersonic wind tunnel experiment on aerodynamic characteristics and winglets effects of the tapered supersonic biplane Peer-reviewed

Takashi Fujisono, Hiroshi Yamashita, Atsushi Toyoda, Hiroki Nagai, Keisuke Asai, Takashi Matsuno, Hiromitsu Kawazoe, Shinkyu Jeong, Shigeru Obayashi

ASME-JSME-KSME 2011 Joint Fluids Engineering Conference, AJK 2011　1　(PARTS A, B, C, D)　3431-3440　2011

DOI： 10.1115/AJK2011-15015 　
Planetary Locomotion‐惑星探査の新しい可能性

浅井圭介, 永井大樹

日本航空宇宙学会年会講演会講演集(CD-ROM)　42nd　ROMBUNNO.B04　2011
火星大気風洞を用いた空力実験

安養寺正之, 野瀬慶, 伊田真悟, 沼田大樹, 永井大樹, 浅井圭介

日本航空宇宙学会年会講演会講演集(CD-ROM)　42nd　ROMBUNNO.B05　2011
Phosphorを用いた高温測定用感温塗料の評価

澤村亮輔, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(11-001(CD-ROM))　ROMBUNNO.P05　2011

ISSN： 1349-113X
火星大気中のはく離制御へのプラズマアクチュエータ適用

田中慎一, 安養寺正之, 沼田大樹, 永井大樹, 浅井圭介

日本航空宇宙学会北部支部講演会ならびに再使用型宇宙推進系シンポジウム講演論文集　2011-12th　201-206　2011
火星探査航空機の空力性能

永井大樹, 浅井圭介, 大山聖, 野々村拓, 安養寺正之, 藤井孝藏, 米本浩一, 越智廣志, 小池勝, 岡本正人

飛行機シンポジウム講演集(CD-ROM)　49th　ROMBUNNO.3F2　2011
低レイノルズ数・高亜音速における三角翼型の空力特性の評価

諏訪哲也, 野瀬慶, 沼田大樹, 永井大樹, 浅井圭介

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　43rd-2011　ROMBUNNO.1D09　2011
角柱と壁面の非定常空力干渉に関する実験的研究

山崎真一, 依田大輔, 沼田大樹, 永井大樹, 浅井圭介

日本航空宇宙学会北部支部講演会ならびに再使用型宇宙推進系シンポジウム講演論文集　2011-12th　191-194　2011
火星探査用小型飛行機の検討

大山聖, 永井大樹, 竹内伸介, 豊田裕之, 砂田茂, 得竹浩, 小川博之, 戸田和朗, 小池勝, 元田敏和, 藤田和央

日本航空宇宙学会年会講演会講演集(CD-ROM)　42nd　ROMBUNNO.B03　2011
蛍光油膜法による翼面はく離流れのイメージング

荻田力, 中村勘太, 依田大輔, 沼田大樹, 永井大樹, 浅井圭介

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　43rd-2011　ROMBUNNO.2B09　2011
時系列画像を用いた非定常圧力場の感圧塗料計測

依田大輔, 山崎真一, 杉本珠生, 沼田大樹, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(11-001(CD-ROM))　ROMBUNNO.P11　2011

ISSN： 1349-113X
感圧塗料を用いた低レイノルズ数・高亜音速領域における翼面圧力分布計測

野瀬慶, 安養寺正之, 伊田真悟, 沼田大樹, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(11-001(CD-ROM))　ROMBUNNO.P20　2011

ISSN： 1349-113X
火星大気風洞を用いた低レイノルズ数領域における薄翼の空力特性の研究

永井大樹, 伊田真悟, 野瀬慶, 安養寺正之, 沼田大樹, 浅井圭介

宇宙科学技術連合講演会講演集(CD-ROM)　55th　ROMBUNNO.2G08　2011

ISSN： 1884-1945
セカンダリウィック形状によるループヒートパイプ性能への影響

眞籠耕平, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　55th　ROMBUNNO.2G13　2011

ISSN： 1884-1945
低レイノルズ数領域における石井翼の空力特性評価

安養寺正之, 野々村拓, 大山聖, 藤井孝藏, 野瀬慶, 沼田大樹, 永井大樹, 浅井圭介

宇宙科学技術連合講演会講演集(CD-ROM)　55th　ROMBUNNO.2G07　2011

ISSN： 1884-1945
火星探査飛行機の多目的設計探査

大山聖, 米本浩一, 竹内伸介, 得竹浩, 永井大樹, 砂田茂, 大槻真嗣

宇宙科学技術連合講演会講演集(CD-ROM)　55th　ROMBUNNO.2G01　2011

ISSN： 1884-1945
High-accuracy Calculation of Aerodynamic Heating using Temperature-Sensitive Paint

西潟一樹, 澤村亮輔, 永井大樹

可視化情報学会誌　31　(1)　269-272　2011
Publisher: 可視化情報学会
ISSN： 0916-4731
Development of Temperature-Sensitive Paint for Cryogenic Cavitation Test

藤井祥太, 新井山一樹, 永井大樹

可視化情報学会誌　31　(1)　273-276　2011
Publisher: 可視化情報学会
ISSN： 0916-4731
Pressure-Sensitive Paint Measurement of Unsteady Flow Fields around a High-Speed Train Model

依田大輔, 山崎真一, 永井大樹, 浅井圭介, 森田潔, 阿部行伸

可視化情報学会誌　30　(Suppl.2)　85-86　2010/10/15

ISSN： 0916-4731
機能性分子センサーを用いた極限環境下における熱流体計測法

永井大樹

日本機械学会年次大会講演論文集　2010　(Vol.9)　159-160　2010/09/04
Study of Temperature-sensitive-paint composed of phosphor and ceramic compound for high temperature

澤村亮輔, 永井大樹, 沼田大樹, 浅井圭介

可視化情報学会誌　30　(Suppl.1)　173-176　2010/07/01

ISSN： 0916-4731
Frequency Characteristics of Fast-Responding Pressure-Sensitive Paint

杉本珠生, 依田大輔, 沼田大樹, 永井大樹, 浅井圭介

可視化情報学会誌　30　(Suppl.1)　177-180　2010/07/01
Publisher: 可視化情報学会
ISSN： 0916-4731
Optical Fiber Sensor Capable of Measuring Pressure and Temperature from Luminescent Lifetime

須貝直之, 依田大輔, 沼田大樹, 永井大樹, 浅井圭介

可視化情報学会誌　30　(Suppl.1)　195-200　2010/07/01

ISSN： 0916-4731
Pressure-Sensitive Paint Measurement of Pressure Distributions on an Airfoil at Low Reynolds Number

野瀬慶, 小野直志, 安養寺正之, 沼田大樹, 永井大樹, 浅井圭介

可視化情報学会誌　30　(Suppl.1)　201-206　2010/07/01
Publisher: 可視化情報学会
ISSN： 0916-4731
感温塗料を用いた極超音速流れにおける圧縮コーナー模型表面の温度分布計測

永井大樹, HA Seungwoh, 澤村亮輔, 浅井圭介

衝撃波シンポジウム講演論文集　2009　53-56　2010/03/17
断層シュリーレン法と感圧塗料の複合計測による超音速複葉翼の3次元内部構造の可視化計測

萩原真澄, 永井大樹, 沼田大樹, 浅井圭介

衝撃波シンポジウム講演論文集　2009　29-32　2010/03/17
Development of an experimental small loop heat pipe with PTFE wick Peer-reviewed

Hosei Nagano, Fuyuko Fukuyoshi, Hiroyuki Ogawa, Hiroki Nagai

40th International Conference on Environmental Systems, ICES 2010　2010
Low Reynolds number airfoil testing in a Mars Wind Tunnel Peer-reviewed

Masayuki Anyoji, Kei Nose, Shingo Ida, Daiju Numata, Hiroki Nagai, Keisuke Asai

40th AIAA Fluid Dynamics Conference　2010
Unsteady PSP technique for measuring naturally-disturbed periodic phenomena Peer-reviewed

D. Yorita, H. Nagai, K. Asai, T. Narumi

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition　2010
Experimental study on dynamic instability of re-entry capsule-shaped body using pressure sensitive paint Peer-reviewed

Daisuke Sugimoto, Hiroki Nagai, Keisuke Asai, Koju Hiraki

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition　2010
Characteristics of the Mars Wind Tunnel at Tohoku University in CO <inf>2</inf> operation mode Peer-reviewed

M. Anyoji, S. Ida, K. Nose, D. Numata, H. Nagai, K. Asai

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition　2010
断層シュリーレン法を用いた超音速複葉翼の内部構造の解明

萩原真澄, 永井大樹, 沼田大樹, 浅井圭介

日本航空宇宙学会北部支部講演会ならびに再使用型宇宙推進系シンポジウム講演論文集　2010-11th　162-167　2010
火星大気風洞のCO₂モード運転と測定部気流特性の評価

野瀬慶, 安養寺正之, 沼田大樹, 永井大樹, 浅井圭介

日本航空宇宙学会北部支部講演会ならびに再使用型宇宙推進系シンポジウム講演論文集　2010-11th　211-216　2010
火星大気風洞における低レイノルズ数翼型実験

浅井圭介, 永井大樹, 沼田大樹, 安養寺正之, 伊田真悟, 野瀬慶

宇宙科学技術連合講演会講演集(CD-ROM)　54th　ROMBUNNO.3F06　2010

ISSN： 1884-1945
寿命法による圧力・温度同時計測光ファイバーセンサーの開発

須貝直之, 依田大輔, 沼田大樹, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(10-001(CD-ROM))　JUMYOHONIYORU　2010

ISSN： 1349-113X
火星大気風洞に適用可能な感圧塗料の開発と評価

小野直志, 沼田大樹, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(10-001(CD-ROM))　KASEITAIKIFUDONITEKIYOKANONA　2010

ISSN： 1349-113X
蛍光油膜を用いた鈍頭物体周りの摩擦応力面分布計測

角田智哉, 小山敦史, 依田大輔, 沼田大樹, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(10-001(CD-ROM))　KEIKOYUMAKUOMOCHIITA　2010

ISSN： 1349-113X
小型ループヒートパイプの始動特性(シンク温度,重力方向の影響について)

玉村大道, 永井大樹, 真籠耕平, 長野方星, 小川博之

宇宙科学技術連合講演会講演集(CD-ROM)　54th　ROMBUNNO.2J02　2010

ISSN： 1884-1945
航空宇宙分野における高温領域への適用を目指した感温塗料の開発

澤村亮輔, HA Seungwon, 永井大樹, 浅井圭介, 垣花眞人

日本航空宇宙学会北部支部講演会ならびに再使用型宇宙推進系シンポジウム講演論文集　2010-11th　81-86　2010
時系列画像処理による感圧塗料の非定常流計測

依田大輔, 沼田大樹, 永井大樹, 浅井圭介

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　42nd-2010　ROMBUNNO.2C6　2010
音響共鳴管を用いた感圧塗料の周波数応答性評価

杉本珠生, 依田大輔, 沼田大樹, 永井大樹, 浅井圭介

日本航空宇宙学会北部支部講演会ならびに再使用型宇宙推進系シンポジウム講演論文集　2010-11th　101-104　2010
東北大学における低速・非定常感圧塗料計測の現状と今後の展望

依田大輔, 杉本珠生, 鳴海智博, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(10-001(CD-ROM))　TOHOKUDAIGAKUNIOKERU　2010

ISSN： 1349-113X
フォスファーを用いたロケットエンジン内温度分布計測技術の開発

澤村亮輔, 永井大樹, 浅井圭介

宇宙科学技術連合講演会講演集(CD-ROM)　54th　ROMBUNNO.3B02　2010

ISSN： 1884-1945
蛍光油膜を用いた二次元翼における摩擦応力分布のイメージング計測

小山敦史, 角田智哉, 沼田大樹, 永井大樹, 浅井圭介

日本航空宇宙学会北部支部講演会ならびに再使用型宇宙推進系シンポジウム講演論文集　2010-11th　91-94　2010
PTFE多孔質を用いた小型ループヒートパイプの基本特性および温度制御性

福吉芙由子, 長野方星, 小川博之, 永井大樹

日本伝熱シンポジウム講演論文集(CD-ROM)　47th　ROMBUNNO.I214　2010

ISSN： 1346-1532
感圧塗料を用いた再突入カプセル型物体の遷音速領域における圧力分布計測―背圧変動分布と位相遅れ―

永井大樹, 杉本大輔, 浅井圭介, 平木講儒

日本航空宇宙学会年会講演会講演集(CD-ROM)　41st　ROMBUNNO.A31　2010
低圧環境下における熱線流速計の感度特性

沼田大樹, 杉野泰啓, 安養寺正之, 永井大樹, 浅井圭介

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集(CD-ROM)　42nd-2010　ROMBUNNO.2C13　2010
火星大気風洞の動作特性評価―現状と計画―

安養寺正之, 野瀬慶, 沼田大樹, 永井大樹, 浅井圭介

日本航空宇宙学会年会講演会講演集(CD-ROM)　41st　ROMBUNNO.C07　2010
カルマン渦が誘起する非定常圧力場の感圧塗料計測

依田大輔, 沼田大樹, 永井大樹, 浅井圭介

日本機械学会流体工学部門講演会講演論文集(CD-ROM)　88th　ROMBUNNO.1501　2010

ISSN： 1348-2882
Improvement in Operating Characteristics of a Small Loop Heat Pipe with Active Control of a Reservoir

FUKUYOSHI Fuyuko, NAGANO Hosei, OGAWA Hiroyuki, NAGAI Hiroki

AEROSPACE TECHNOLOGY JAPAN, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES　9　(9)　49-55　2010
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/astj.9.49 　

ISSN： 1884-0477

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This paper reports test results of active control of heat transfer performance of a small loop heat pipe (LHP) with a thermoelectric converter (TEC) in an atmospheric condition. The TEC is attached to a reservoir of the LHP to control the operating temperature by heating and cooling using a bipolar power supply. Tests were conducted by varying the evaporator power, the reservoir set point temperature, and the condenser sink temperature. The test results showed that the TEC is able to control the LHP operating with small electric power. The test results also demonstrated enhancement of the start-up success by maintaining a constant reservoir temperature during the start-up process. Forced shut-off of the loop operation by rapid heating of the reservoir was also demonstrated.
W0503-(2) 機能性分子センサーを用いた極限環境下における熱流体計測法(【W0503】EFDワークショップ『PSPによる表面情報の可視化計測』,ワークショップ)

永井大樹

年次大会講演資料集　2010　(0)　159-160　2010
Publisher: 一般社団法人日本機械学会
DOI： 10.1299/jsmemecjsm.2010.9.0_159 　
1501 Pressure-Sensitive Paint Measurement of Unsteady Pressure Fields induced by Karman Vortex

YORITA Daisuke, NUMATA Daiju, NAGAI Hiroki, ASAI Keisuke

The Proceedings of the Fluids engineering conference　2010　(0)　435-436　2010
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmefed.2010.435 　

ISSN： 1348-2882

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To understand unsteady flow phenomena around a body, it is important to measure time-resolved surface pressure distributions with high spatial resolution. Pressure Sensitive Paint (PSP) has a capability of providing high-resolution pressure images. In this study, we propose a new PSP technique to obtain time-resolved surface pressure distributions by using conditional sampling of time-series PSP images. To obtain high SNR data, the high-speed camera images are phase-averaged after image acquisition, using a simultaneously-measured pressure transducer data to detect a phase of each image. This method allows us to obtain high SNR images at arbitrary phase of the periodic phenomena using a simplify measurement system and image processing. The effectiveness of the present method was evaluated by applying it to a 3-D square cylinder in low-speed wind tunnel testing. As a result of this experiment, we could obtain time-resolved unsteady pressure images around the square cylinder caused by periodic vortex shedding.
A fundamental characteristic and temperature controllability of a

FUKUYOSHI Fuyuko, NAGANO Hosei, OGAWA Hiroyuki, NAGAI Hiroki

Proceedings of National Heat Transfer Symposium　2010　(0)　239-239　2010
Publisher: The Heat Transfer Society of Japan
DOI： 10.11368/nhts.2010.0.239.0 　

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ループヒートパイプ（LHP）は，その熱輸送性能や搭載性が利点となる熱制御デバイスである．本実験ではミッション機器への応用も視野に入れて小型LHPに着目し，その動作特性を解明するためPTFE多孔質を用いた100W級の小型LHPを製作した．そして，熱負荷に対する動作温度の関係など基本性能を取得した．また，熱電変換素子によりリザーバの温度制御を行い，LHP動作温度の制御特性について実験を行い，リザーバ制御の有用性について実験的に示すことができた．
Study of temperature-sensitive-paint consisting of phosphor and ceramic compound for high temperature

澤村亮輔, 永井大樹, 沼田大樹

Journal of the Visualization Society of Japan　30　(0)　173-176　2010
Publisher: 可視化情報学会
ISSN： 0916-4731
Correlation between the Pressure Distributions on Re-entry Capsule Shaped Body and Dynamic Instability

杉本大輔, 永井大樹, 浅井圭介, 平木講儒

日本機械学会年次大会講演論文集　2009　(Vol.5)　285-286　2009/09/12
PSP measurement on an ellipsoid with seams-The effect of seam on the pressure distribution-

瀬尾和哉, 依田大輔, 永井大樹, 白石菜々, 浅井圭介

日本機械学会年次大会講演論文集　2009　(Vol.2)　273-274　2009/09/12
Study of Global heat flux measurement technique in Hypersonic flow using Temperature-Sensitive Paint

永井大樹, HA Seungwon, 浅井圭介

日本機械学会年次大会講演論文集　2009　(Vol.5)　295-296　2009/09/12
高熱輸送小型ループヒートパイプの設計および実験的検証

長野方星, 福吉芙由子, 小川博之, 永井大樹

日本混相流学会年会講演会講演論文集　2009　62-63　2009/08
Development and evaluation of pressure-sensitive paint applicable to surface pressure measurements in Mars Wind Tunnel

小野直志, 永井大樹, 浅井圭介

可視化情報学会誌　29　(Suppl.1)　275-278　2009/07/01

DOI： 10.3154/jvs.29.275 　

ISSN： 0916-4731
Measurement Error and Accuracy Evaluation of Pressure Sensitive Paint Measurement in a Low-speed Flow

依田大輔, 永井大樹, 浅井圭介, 田中真悟, 石田圭太郎

可視化情報学会誌　29　(Suppl.1)　269-274　2009/07/01

DOI： 10.3154/jvs.29.269 　

ISSN： 0916-4731
PSP Measurement of a Rugby Ball and Visualizing Pareto-optimal Solutions for a Fluctuating Punted Kick in Rugby

瀬尾和哉, 依田大輔, 永井大樹

可視化情報学会誌　29　(Suppl.1)　357-362　2009/07/01

DOI： 10.3154/jvs.29.357 　

ISSN： 0916-4731
Measurement Error and Accuracy Evaluation of Pressure Sensitive Paint Measurement in a Low-speed Flow

YORITA Daisuke, NAGAI Hiroki, ASAI Keisuke, TANAKA Shingo, ISHIDA Keitaro

Journal of the Visualization Society of Japan　29　(1)　269-274　2009/07/01
Publisher: 可視化情報学会
ISSN： 0916-4731
Development and evaluation of pressure-sensitive paint applicable to surface pressure measurements in Mars Wind Tunnel

ONO Tadashi, NAGAI Hiroki, ASAI Keisuke

Journal of the Visualization Society of Japan　29　(1)　275-278　2009/07/01
Publisher: 可視化情報学会
ISSN： 0916-4731
PSP Measurement of a Rugby Ball and Visualizing Pareto-optimal Solutions for a Fluctuating Punted Kick in Rugby

SEO Kazuya, YORITA Daisuke, NAGAI Hiroki

Journal of the Visualization Society of Japan　29　(1)　357-362　2009/07/01
Publisher: 可視化情報学会
ISSN： 0916-4731
光を発する塗料「感圧塗料」光る色素で圧力をはかる

浅井圭介, 永井大樹

化学と教育　57　(3)　128-129　2009/03/20

DOI： 10.20665/kakyoshi.57.3_128 　

ISSN： 0386-2151
超音速複葉翼の始動過程に対する3次元性の影響

大山創史, 藤園崇, 永井大樹, 浅井圭介, 大林茂

衝撃波シンポジウム講演論文集　2008　269-272　2009/03/17
極超音速流中のエアロスパイク模型周りの衝撃波構造と熱流束との関係について

HA Seungwon, 永井大樹, 浅井圭介, 中北和之, 坪井伸幸

衝撃波シンポジウム講演論文集　2008　385-388　2009/03/17
実験/計算融合によるソニックブーム推定方法の高精度化

大林茂, 浅井圭介, 永井大樹, 小川俊広, 倉谷尚志

宇宙航空研究開発機構契約報告 JAXA-CR-　(08-002)　7-17　2009/02/27

ISSN： 1349-1148
Visualization study of film boiling in saturated He II under low gravity environment

N. Kimura, S. Takada, S. Gotoh, H. Kawamata, M. Iida, M. Murakami, H. Nakai, H. Nagai, M. Mamiya

Proc. of ICEC 22　377-382　2009
Development of low density wind tunnel to simulate atmospheric flight on Mars Peer-reviewed

M. Anyoji, H. Nagai, K. Asai

47th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition　2009
Heat flux measurement techniques over the protuberance at the hypersonic flow of Mach 7 Peer-reviewed

Hyoung Jin Lee, In Seuck Jeung, Bok Jik Lee, Seong Lyong Kim, Insun Kim, Osamu Imamura, Kojiro Suzuki, Koji Okamoto, Seungwon Ha, Hiroki Nagai, Keisuke Asai

16th AIAA/DLR/DGLR International Space Planes and Hypersonic Systems and Technologies Conference　2009
東北大火星大気風洞の開発と性能試験

安養寺正之, 沼田大樹, 永井大樹, 浅井圭介

宇宙科学技術連合講演会講演集(CD-ROM)　53rd　1G11　2009

ISSN： 1884-1945
宇宙用小型ループヒートパイプの開発

岡本篤, 小川博之, 長野方星, 永井大樹, 村上正秀

宇宙科学技術連合講演会講演集(CD-ROM)　53rd　2J07　2009

ISSN： 1884-1945
角柱側面に生じる非定常圧力変動のPSP計測

依田大輔, 永井大樹, 浅井圭介, 鳴海智博

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集　41st-2009　203-206　2009
超音速複葉翼の始動過程に対する3次元性の影響

藤園崇, 大山創史, 永井大樹, 大林茂, 浅井圭介

日本航空宇宙学会北部支部講演会ならびに再使用型宇宙推進系シンポジウム講演論文集　2009-10th　52-57　2009
感温塗料とCFD計算の融合による極超音速流中の空力加熱予測

永井大樹, 浅井圭介, 坪井伸幸

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集　41st-2009　103-106　2009
リザーバ能動制御によるループヒートパイプの熱制御性向上に関する研究

福吉芙由子, 小川博之, 長野方星, 永井大樹

日本航空宇宙学会北部支部講演会ならびに再使用型宇宙推進系シンポジウム講演論文集　2009-10th　247-249　2009
火星大気風洞の測定部気流特性について(第一報)

安養寺正之, 伊田真悟, 永井大樹, 浅井圭介

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集　41st-2009　211-214　2009
Thermal performance evaluation by gravity effect of a miniature loop heat pipe

永井大樹, 長野方星, 福吉芙由子, 小川博之

日本伝熱シンポジウム講演論文集(CD-ROM)　46th　ROMBUNNO.G-333　2009

ISSN： 1346-1532
Active control of operating characteristics for loop heat pipe with thermoelectric converters

福吉芙由子, 長野方星, 小川博之, 永井大樹

日本伝熱シンポジウム講演論文集(CD-ROM)　46th　ROMBUNNO.G-321　2009

ISSN： 1346-1532
トンネル内を走行する高速列車に生じる振動現象

小寺健幸, 永井大樹, 浅井圭介, 寺島修

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集　41st-2009　107-110　2009
低圧下におけるDBDプラズマアクチュエータの作動特性

高垣雅彦, 永井大樹, 浅井圭介

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集　41st-2009　285-288　2009
Effect of Amount of Fluid Charge in Thermal Performance of Loop Heat Pipe

小野川英, 長野方星, 福吉芙由子, 小川博之, 永井大樹

日本伝熱シンポジウム講演論文集(CD-ROM)　46th　ROMBUNNO.G-312　2009

ISSN： 1346-1532
月面長期滞在に向けた高性能ループヒートパイプの研究

長野方星, 福吉芙由子, 小川博之, 永井大樹

日本航空宇宙学会北部支部講演会ならびに再使用型宇宙推進系シンポジウム講演論文集　2009-10th　239-242　2009
感圧塗料を用いた再突入カプセル型物体の動的不安定現象解明

杉本大輔, 永井大樹, 浅井圭介, 平木講儒

日本航空宇宙学会北部支部講演会ならびに再使用型宇宙推進系シンポジウム講演論文集　2009-10th　118-123　2009
Three-Dimensional Effects on Surface Heat Flux of a Blunt-Nosed Body with an Aerospike in Hypersonic Flow

坪井伸幸, 永井大樹, 浅井圭介

日本機械学会流体工学部門講演会講演論文集(CD-ROM)　87th　ROMBUNNO.0604　2009

ISSN： 1348-2882
0604 Three-Dimensional Effects on Surface Heat Flux of a Blunt-Nosed Body with an Aerospike in Hypersonic Flow

TSUBOI Nobuyuki, NAGAI Hiroki, ASAI Keisuke

The Proceedings of the Fluids engineering conference　2009　(0)　253-254　2009
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmefed.2009.253 　

ISSN： 1348-2882

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A blunt body in hypersonic flow is subjected to severe aerodynamic heating and drag. This is one of the most critical problems of designing the hypersonic vehicles such as Reusable Launch Vehicles(RLV). It is well known that the spiked-nose(aerospike)concept is effective to reduce aerodynamic drag on asymmetric blunt bodies in hypersonic flow. In this study, we investigated the heat flux distribution on a blunt-nosed body with an aerospike in hypersonic flow. The flow field around a blunt-nosed body is calculated by the full Navier-Stokes simulations to compare with the experimental data such as Schlieren photographs and TSP(Temperature Sensitive Paint)images. It was found that the heat flux distributions changes widely with the angle of attack. Moreover, the correlation between heat flux and the flow and the flow field exists due to the shock/shock interaction patterns for various angle-of-attacks.
S0506-1-1 PSP measurement on an ellipsoid with seams : The effect of seam on the pressure distribution

SEO Kazuya, YORITA Daisuke, NAGAI Hiroki, Shiroishi Nana, ASAI Keisuke

The proceedings of the JSME annual meeting　2009　(0)　273-274　2009
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.2009.2.0_273 　

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In this paper, the effect of the seams of a rugby ball on the side force is described in order to show why the punted kick fluctuates during the flight. Measurement of the aerodynamic force on a non-spinning rugby ball reveals that the side force depends on the position of the seam as well as the angle of attack. It was found from PSP measurements that the seam of the ball is the trigger for initiating low pressure. The seam of the ball produces an asymmetrical pressure distribution on the sides. Therefore, a slower spinning ball fluctuates during flight.
S1904-1-1 Correlation between the Pressure Distributions on Re-entry Capsule Shaped Body and Dynamic Instability

SUGIMOTO Daisuke, NAGAI Hiroki, ASAI Keisuke, HIRAKI Koju

The proceedings of the JSME annual meeting　2009　(0)　285-286　2009
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.2009.5.0_285 　

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A fast responding Pressure-Sensitive Paint (PSP) using polymer/ceramic binder and image capturing technique called Phase Lock Method were used to visualize the unsteady pressure distributions on a capsule-shaped body undergoing the pitching motion. In addition, schlieren visualization using high-speed video camera was used to take a picture around the flowfield of the model, together with pitch angle measurement using a potentiometer. As a result, the strength and the location of vortices behind the capsule varies depending on the direction of the oscillating motion, and the base pressure distributions are related to the dynamic motion of the vortices from the edge of the capsule.
S1904-2-1 Study of Global heat flux measurement technique in Hypersonic flow using Temperature-Sensitive Paint

NAGAI Hiroki, HA Seungwon, ASAI Keisuke

The proceedings of the JSME annual meeting　2009　(0)　295-296　2009
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.2009.5.0_295 　

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Heat flux measurement in a hypersonic wind tunnel is one of indispensable requirements for designing the next generation re-entry vehicle. Heat flux is usually calculated from a temporal change in temperature on the model surface. Temperature-Sensitive Paint (TSP) is a global temperature measurement technique based on photochemical reaction. In this study, TSP technique was applied to a hypersonic shock tunnel test and the measurement accuracy was investigated with a different TSP thickness. From that result, the optimum thickness of TSP was found to be 0.2μm. Then, the heat flux distribution of a blunt-nosed body with an aerospike was investigated by an optimized TSP thickness
「感圧塗料」光る色素で圧力をはかる(ヘッドライン:光を発する塗料)

浅井圭介, 永井大樹

化学と教育　57　(3)　128-129　2009
Publisher: 公益社団法人日本化学会
DOI： 10.20665/kakyoshi.57.3_128 　

ISSN： 0386-2151

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感圧塗料は,機能性化合物の分子薄膜をセンサーとして用い,その発光から物体表面での圧力場を画像化する技術である。これらのセンサーは,物体上の物理量を面情報として可視化するだけでなく,従来のセンサーが設置できないような局所や微小物体にも適用できる。本解説では,この感圧塗料の基礎と作り方,簡単なデモ実験の方法について解説し,最後に航空宇宙分野の研究開発に適用されている感圧塗料の実用例を紹介する。
Measurement Error and Accuracy Evaluation ofPressure Sensitive Paint Measurement in a Low-speed Flow

YORITA Daisuke, NAGAI Hiroki, ASAI Keisuke, TANAKA Shingo, ISHIDA Keitaro

Journal of the Visualization Society of Japan　29　(1)　269-269　2009
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.29.269 　

ISSN： 0916-4731
Development and evaluation of pressure-sensitive paint applicable to surface pressure measurements in Mars Wind Tunnel

ONO Tadashi, NAGAI Hiroki, ASAI Keisuke

Journal of the Visualization Society of Japan　29　(1)　275-275　2009
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.29.275 　

ISSN： 0916-4731
PSP Measurement of a Rugby Ball and Visualizing Pareto-optimal Solutions for a Fluctuating Punted Kick in Rugby

SEO Kazuya, YORITA Daisuke, NAGAI Hiroki

Journal of the Visualization Society of Japan　29　(1)　357-357　2009
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.29.357 　

ISSN： 0916-4731
Effect of Amount of Fluid Charge in Thermal Performance of Loop Heat Pipe

Onogawa Ei, Nagano Hosei, Fukuyoshi Fuyuko, Ogawa Hiroyuki, Nagai Hiroki

Proceedings of National Heat Transfer Symposium　2009　(0)　348-348　2009
Publisher: The Heat Transfer Society of Japan
DOI： 10.11368/nhts.2009.0.348.0 　

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民生および宇宙分野で省エネで高効率な熱輸送技術が強く求められている。本研究では、ウィックとよばれる多孔質材内で発生する毛細管力を利用したループヒートパイプ技術に着目し、その高性能化と実用化に向けた研究開発に取り組んでいる。本報告では作動流体のチャージ量変化に伴う熱特性変化を実験的に明らかにしたので報告する。
Active control of operating characteristics forloop heat pipe with thermoelectric converters

FUKUYOSHI FUYUKO, NAGANO HOSEI, OGAWA HIROYUKI, NAGAI HIROKI

Proceedings of National Heat Transfer Symposium　2009　(0)　351-351　2009
Publisher: The Heat Transfer Society of Japan
DOI： 10.11368/nhts.2009.0.351.0 　

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海外において次世代のスタンダードな熱制御技術として毛細管駆動型二相流体ループ（ループヒートパイプ）の研究開発が進められており、本研究では日本の将来の宇宙ミッションを見据え，100W級の小型ループヒートパイプに着目し研究を行っている。今回、ループヒートパイプのリザーバ/補償チャンバー（Compensation Chamber, CC）の温度制御に熱電交換モジュールを用いて、ループヒートパイプの動作特性について実験および評価を行ったので報告する。
Thermal performance evaluation by gravity effect of a miniature loop heat pipe

Nagai Hiroki, Nagano Hosei, Fukuyoshi Fuyuko, Ogawa Hiroyuki

Proceedings of National Heat Transfer Symposium　2009　(0)　356-356　2009
Publisher: The Heat Transfer Society of Japan
DOI： 10.11368/nhts.2009.0.356.0 　

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近年、惑星探査や月面着陸などミッションの高度化にともない、より高性能で複雑な熱制御技術が必要とされている。特に、熱環境が複雑に変動するミッションにおいて、衛星の熱設計を高温側および低温側で同時に満足できるような熱制御技術が重要である。そこで、アメリカをはじめ海外では次世代のスタンダードな熱制御技術として毛細管駆動型二相流体ループ（ループヒートパイプ：LHP）が開発されてきた。本研究では日本の将来の宇宙ミッションを見据え、100W級の小型LHPに着目し、これまでにその起動特性ならびに熱輸送特性の評価を行ってきた。今回は、このループヒートパイプの重力方向に対する実験および評価を行ったので報告する。
Study to develop an Evaluation Method of Fluid Force Acting on High-Speed Trains

寺島修, 阿部行伸, 小寺健幸, 永井大樹, 浅井圭介

日本機械学会交通・物流部門大会講演論文集　17th　61-64　2008/12/09
Flow-Induced Vibration of a High-speed Train Running in a Tunnel Peer-reviewed

T.Kodera, H.Nagai, K.Asai, O.Terashima

Proc. KSAS-JSASS Joint International Symposium on Aerospace Engineering　267-272　2008/11
小型ループヒートパイプの熱流動解析モデルの構築と実験的検証

長野方星, 福吉芙由子, 小川博之, 永井大樹

日本混相流学会年会講演会講演論文集　2008　132-133　2008/08
PSP Measurement of the Leeward-Side Pressure Distribution of a Simplified Car Model in Yaw

依田大輔, 永井大樹, 浅井圭介, 田中真悟, 石田圭太郎

可視化情報学会誌　28　(Suppl.1)　97-100　2008/07/01

DOI： 10.3154/jvs.28.97 　

ISSN： 0916-4731
PSP Measurement of the Leeward-Side Pressure Distribution of a Simplified Car Model in Yaw

YORITA Daisuke, NAGAI Hiroki, ASAI Keisuke, TANAKA Shingo, ISHIDA Keitaro

Journal of the Visualization Society of Japan　28　(1)　97-100　2008/07/01
Publisher: 可視化情報学会
ISSN： 0916-4731
極超音速流中のエアロスパイク模型に流入する熱流束分布の可視化

HA Seungwon, 三浦悠佑, 永井大樹, 浅井圭介, 中北和之

衝撃波シンポジウム講演論文集　2007　349-352　2008/03/17
超音速複葉翼の衝撃波干渉流れに関する可視化研究

大山創史, 永井大樹, 倉谷尚志, 小川俊広, 浅井圭介

衝撃波シンポジウム講演論文集　2007　219-220　2008/03/17
感温塗料を用いた空力加熱計測手法の東大柏極超音速風洞への適用

永井大樹, HA SeungWon, 三浦悠佑, 浅井圭介

衝撃波シンポジウム講演論文集　2007　357-360　2008/03/17
Experimental study on interference flow of a supersonic Busemann Biplane

永井大樹, 齋藤賢一, 小川俊広, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(07-016)　22-27　2008/02/29

ISSN： 1349-113X
Study on Thermal Performances of a Small Loop Heat Pipe Peer-reviewed

Hosei Nagano, Hiroki Nagai, Fuyuko Fukuyoshi, Hiroyuki Ogawa

JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY　3　(2)　355-367　2008

DOI： 10.1299/jtst.3.355 　

ISSN： 1880-5566
Evaluation of plasma actuator performance in Martian atmosphere for applications to Mars airplanes Peer-reviewed

Masahiko Takagaki, Susumu Isono, Hiroki Nagai, Keisuke Asai

4th AIAA Flow Control Conference　2008
Surface pressure and flow field behind an oscillating fence submerged in turbulent boundary layer Peer-reviewed

Manjinder S. Saini, Jonathan W. Naughton, Taro Yamashita, Hiroki Nagai, Keisuke Asai

4th AIAA Flow Control Conference　2008
Enhancement of pressure-sensitive paint emission using localized surface plasmon resonance for shock tunnel applications Peer-reviewed

Y. Miura, H. Nagai, K. Asai, K. Nakakita

46th AIAA Aerospace Sciences Meeting and Exhibit　2008
Experimental study on interference flow of a supersonic busemann biplane using pressure-sensitive paint technique Peer-reviewed

Hiroki Nagai, Soshi Oyama, Toshiyuki Ogawa, Naoshi Kuratani, Keisuke Asai

ICAS Secretariat - 26th Congress of International Council of the Aeronautical Sciences 2008, ICAS 2008　2　3060-3068　2008
Pressure-Sensitive Paint Measurement of Unsteady Pressure Field behind an oscillating Fence Actuator

永井大樹, 山下太郎, 浅井圭介, SINGH Manjinder

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集　40th-2008　373-376　2008
宇宙機搭載を目指した小型ループヒートパイプの性能評価試験

永井大樹, 長野方星, 福吉芙由子, 小川博之

日本航空宇宙学会北部支部講演会講演論文集　2008　205-209　2008
火星大気環境下に適用可能な感圧塗料の開発

小野直志, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(08-012(CD-ROM))　KASEITAIKIKANKYOKA　2008

ISSN： 1349-113X
Numerical Study on Shock Wave Interaction around Compresion Corner with 30 degrees in Hypersonic Flow: Structure of Shock Wave and Heat Flux

坪井伸幸, 永井大樹, 浅井圭介, 大門優, 嶋田徹

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集　40th-2008　291-294　2008
火星大気におけるプラズマアクチュエータの有効性

磯野晋, 高垣雅彦, 永井大樹, 浅井圭介

日本航空宇宙学会北部支部講演会講演論文集　2008　61-66　2008
デルタ翼Wing Rock現象の受動制御

西村洋介, 杉本大輔, 永井大樹, 浅井圭介

日本航空宇宙学会北部支部講演会講演論文集　2008　119-124　2008
火星大気飛行を模擬する低密度風洞の設計開発

佐藤武志, 永井大樹, 浅井圭介

日本航空宇宙学会北部支部講演会講演論文集　2008　67-72　2008
機能性分子センサーを用いたマイクロスラスター内部流れの研究

倉科大輔, 永井大樹, 浅井圭介

日本航空宇宙学会北部支部講演会講演論文集　2008　7-12　2008
Dynamic Testing of a Delta Wing in Rocking Motion as an Example of EFD/CFD Hybrid Simulation

浅井圭介, 永井大樹, 宮路幸二

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集　40th-2008　145-148　2008
多孔質膜を用いた差圧応答型PSPの開発と応用

依田大輔, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(08-012(CD-ROM))　TAKOSHITSUMAKUOMOCHIITA　2008

ISSN： 1349-113X
Thermal performance of a miniature loop heat pipe for spacecraft thermal control system

永井大樹, 長野方星, 福吉芙由子, 小川博之

日本伝熱シンポジウム講演論文集(CD-ROM)　45th　A132　2008

ISSN： 1346-1532
3306 Study to develop an Evaluation Method of Fluid Force Acting on High-Speed Trains

Terashima Osamu, Abe Yukinobu, Kodera Takeyuki, Nagai Hiroki, Asai Keisuke

The Proceedings of the Transportation and Logistics Conference　2008　(0)　61-64　2008
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmetld.2008.17.61 　

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One of the aerodynamic issues affecting high-speed trains is the flow-induced vibration of the tail car when cruising through a tunnel, which results in reduced passenger comfort. The objective of this study is to develop a method to evaluate the fluid force acting on high-speed trains. We conducted wind tunnel tests of a simplified train model using a flat plate to simulate the effect of the tunnel wall. Pressure transducers were used to measure unsteady pressure fluctuations on the tunnel wall, and Pressure Sensitive Paint (PSP) was applied to measure time-averaged surface pressure distribution on the train model. We also conducted Large Eddy Simulation (LES) for the same model and test conditions. The results indicated that by applying LES, we were also to reconstruct the spectrum of pressure fluctuation on the tunnel wall that we observed in the wind tunnel experiment.
Thermal performance of a Miniature Loop Heat Pipe for Spacecraft Thermal Control System

Nagai Hiroki, Nagano Hosei, Fukuyoshi Fuyuko, Ogawa Hiroyuki

Proceedings of National Heat Transfer Symposium　2008　(0)　8-8　2008
Publisher: The Heat Transfer Society of Japan
DOI： 10.11368/nhts.2008.0.8.0 　

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近年、惑星探査や月面着陸などミッションの高度化に伴い、より高性能で複雑な熱制御技術が必要とされている。特に、熱環境が複雑に変動するミッションにおいて、衛星の熱設計を高温側および低温側で同時に満足できるような熱制御技術が重要である。そこで、アメリカをはじめ海外では次世代のスタンダードな熱制御技術として毛細管駆動型二相流体ループ（ループヒートパイプ：LHP）が開発されてきた。本研究では日本の将来の宇宙ミッションを見据え、100W級の小型LHPに着目し、その起動特性ならびに熱輸送特性の評価を行った。
Study on a Small Loop Heat Pipe (Improvement of Loop Operating Characteristics with Active Temperature Control of a Reservoir)

長野方星, 福吉芙由子, 小川博之, 永井大樹

日本機械学会熱工学コンファレンス講演論文集　2007　381-382　2007/11/23
感圧・感温センシングのための色素連結型酸素透過性高分子の開発

小幡誠, 満尾和徳, 永井大樹, 浅井圭介, 矢野重信

酸化反応討論会講演要旨集　40th　149-151　2007/11/16
Development of luminescent differential-Pressure sensor based on porous membrane

依田大輔, 永井大樹, 浅井圭介

可視化情報学会誌　27　(Suppl.1)　27-28　2007/07/01

DOI： 10.3154/jvs.27.Supplement1_27 　

ISSN： 0916-4731
Pressure-Sensitive Paint Measurement of Flow around High-Speed Trains with Different Tail Shapes

小寺健幸, 山下太郎, 浅井圭介, 永井大樹, 森田潔

可視化情報学会誌　27　(Suppl.1)　13-16　2007/07/01

DOI： 10.3154/jvs.27.Supplement1_13 　

ISSN： 0916-4731
Pressure-Sensitive Paint Measurement of Flow around High-Speed Trains with Different Tail Shapes

KODERA Takeyuki, YAMASHITA Taro, ASAI Keisuke, NAGAI Hiroki, MORITA Kiyoshi

Journal of the Visualization Society of Japan　27　13-16　2007/07/01
Publisher: 可視化情報学会
ISSN： 0916-4731
Development of luminescent differential-pressure sensor based on porous membrane

YORITA Daisuke, NAGAI Hiroki, ASAI Keisuke

可視化情報学会誌 = Journal of the Visualization Society of Japan　27　27-28　2007/07/01

ISSN： 0916-4731
感温塗料を用いたエアロスパイクによる極超音速空力加熱の可視化実験

HA Seungwon, 石黒雄一, 三浦悠佑, 永井大樹, 浅井圭介, 中北和之

衝撃波シンポジウム講演論文集　2006　131-134　2007/03/15
極超音速空力加熱に対する衝撃波干渉の影響

石黒雄一, 三浦悠佑, 永井大樹, 浅井圭介, 中北和之

衝撃波シンポジウム講演論文集　2006　121-124　2007/03/15
Visualization of hypersonic compression corner flows using temperature- And pressure-sensitive paints Peer-reviewed

Y. Ishiguro, H. Nagai, K. Asai, K. Nakakita

Collection of Technical Papers - 45th AIAA Aerospace Sciences Meeting　2　1331-1342　2007
Unsteady flow measurements of a slender delta wing in wing rock motion Peer-reviewed

Yuichi Hirose, Hiroki Nagai, Keisuke Asai

Collection of Technical Papers - 45th AIAA Aerospace Sciences Meeting　2　1401-1412　2007
Development of pressure-sensitive paint technique in a supersonic indraft wind tunnel and its application to a busemann biplane Peer-reviewed

K. Saito, H. Nagai, T. Ogawa, K. Asai

ICIASF Record, International Congress on Instrumentation in Aerospace Simulation Facilities　2007

DOI： 10.1109/ICIASF.2007.4380886 　

ISSN： 0730-2010
Thermal Performance of a Miniature Loop Heat Pipe(1st Rept. Evaluation of Start-up and Heat Transfer Performansces)

福吉芙由子, 長野方星, 小川博之, 永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　51st　3J15　2007

ISSN： 1884-1945
多孔質膜を用いた差圧応答型PSPの開発

依田大輔, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(07-024(CD-ROM))　TAKOSHITSUMAKUOMOCHIITA　2007

ISSN： 1349-113X
機能性分子センサーの燃料電池開発への応用

稲垣俊, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(07-024(CD-ROM))　KINOSEIBUNSHISENSA　2007

ISSN： 1349-113X
Experimental study on interference flow of a supersonic Busemann Biplane

齋藤賢一, 小川俊広, 永井大樹, 浅井圭介

流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集　39th-2007　13-14　2007
Thermal performance of a Miniature Loop Heat Pipe-The second report, Influence of Gravity Force and Evaluation of Thermal Performance-

永井大樹, 長野方星, 福吉芙由子, 小川博之

宇宙科学技術連合講演会講演集(CD-ROM)　51st　3J16　2007

ISSN： 1884-1945
プラズモン励起感圧・感温塗料の開発と高速流動現象への適用

三浦悠佑, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(07-024(CD-ROM))　PURAZUMONREIKIKAN'ATSU　2007

ISSN： 1349-113X
Evaluation of Lifetime-based Pressure-Sensitive Paint Measurement in Low-speed Flow

Yamashita Taro, Nagai Hiroki, Asai Keisuke

Journal of the Visualization Society of Japan　27　(1)　17-18　2007
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.27.Supplement1_17 　

ISSN： 0916-4731

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The lifetime-based method has been applied to Pressure-Sensitive Paint (PSP) measurement in low-speed flow. Based on theoretical considerations and sample tests, a method to calculate pressure using "a-priori" method was proposed. In this method, pressure is related to the ratio of the luminescent intensity ratios obtained at two different gates between the wind-on and wind-off conditions, multiplied by a correction factor calculated from the single-point measurement of model substrate temperature. In order to evaluate the effectiveness of this method, a simplified car model was tested in a low-speed wind tunnel. It was shown that the effects of non-uniform distributions of lifetime and temperature could be cancelled out by the present method. The result obtained by the lifetime method was in good agreement with those of pressure taps and the intensity method.
F231 Study on a Small Loop Heat Pipe : Improvement of Loop Operating Characteristics with Active Temperature Control of a Reservoir

Nagano Hosei, Fukuyoshi Fuyuko, Ogawa Hiroyuki, Nagai Hiroki

The Proceedings of the Thermal Engineering Conference　2007　(0)　381-382　2007
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmeted.2007.381 　

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This paper presents an experimental study to investigate the effectiveness of using a thermoelectric converter to control the loop heat pipe operating temperature. The compensation chamber (CC) was controlled at the set point temperature by cooling and heating the TEC module, of which one side is attached to the CC and the other side is connected to the evaporator through a thermal strap. The test results show that the TEC can control the operating temperature to the set point temperature. The power saving by using the TEC was also demonstrated.
Pressure-Sensitive Paint Measurement of Flow around High-Speed Trains with Different Tail Shapes

KODERA Takeyuki, YAMASHITA Taro, ASAI Keisuke, NAGAI Hiroki, MORITA Kiyoshi

Journal of the Visualization Society of Japan　27　(1)　13-16　2007
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.27.Supplement1_13 　

ISSN： 0916-4731

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Optimizing the performance and increasing the comfort of high-speed trains require the knowledge of aerodynamic effects of a train shape. One of the most critical problems is a compression wave caused by a train entering a tunnel. This noise mainly depends on the cross-sectional area distribution of a train nose. On the other hand, the aerodynamic drag, the stability for side wind, and the low-frequency vibration are attributed to tail shapes. In this study, we studied the effects of train tail shapes on the flow field experimentally. Two models having the same cross-sectional area distribution but with different tail shapes were tested in a low-speed wind tunnel. To analysis the flow field around the model, we used pressure sensitive paint and oil flow techniques. As a result, we could identify the effects of tail shapes for pressure drag and cross wind stability.
Development of luminescent differential-pressure sensor based on porous membrane

YORITA Daisuke, NAGAI Hiroki, ASAI Keisuke

Journal of the Visualization Society of Japan　27　(1)　27-28　2007
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.27.Supplement1_27 　

ISSN： 0916-4731

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Pressure-Sensitive Paint (PSP) is applied to various wind tunnel tests as a useful technique to measure pressure distribution on model surfaces. PSP is inherently an absolute pressure sensor so that it is difficult to use this technique in low-speed flow where pressure change on a model is very small. To measure pressure with a high degree of accuracy at low speeds, we have developed a new type of PSP that responds to differential pressure rather than absolute pressure. This novel technique uses porous membrane through which gas containing no oxygen (e.g. nitrogen) is transported from the backside to the front side by pressure difference between the two. The transported gas purges oxygen near the surface and luminescence of PSP is enhanced. The results of sample tests show that the pressure sensitivity of the new PSP is higher than that of the current PSP by a factor of 100 times or more. In addition, the response of this sensor to differential pressure is almost linear and highly reproducible.
Effect of Temperature-Sensitive Paint Layer on Global Heat Transfer Measurement in Hypersonic Flow

永井大樹, 近江俊輔, 浅井圭介, 中北和之

可視化情報学会誌　26　(Suppl.1)　201-204　2006/07/01

DOI： 10.3154/jvs.26.Supplement1_201 　

ISSN： 0916-4731
PSP Measurement of the Flow around a Simplified Car Model

YAMASHITA Taro, SUGIURA Hikaru, NAGAI Hiroki, ASAI Keisuke, ISHIDA Keitaro

Journal of the Visualization Society of Japan　26　(1)　197-200　2006/07/01
Publisher: 可視化情報学会
ISSN： 0916-4731
Effect of Temperature-Sensitive Paint Layer on Global Heat Transfer Measurement in Hypersonic Flow

NAGAI Hiroki, OHMI Shunsuke, ASAI Keisuke, NAKAKITA Kazuyuki

Journal of the Visualization Society of Japan　26　(1)　201-204　2006/07/01
Publisher: 可視化情報学会
ISSN： 0916-4731
感温塗料を用いた衝撃波干渉による三次元渦構造の可視化

石黒雄一, 近江俊輔, 永井大樹, 浅井圭介, 中北和之

衝撃波シンポジウム講演論文集　2005　79-82　2006/03/16
ブラスト波が誘起する非定常圧力場の画像計測に関する研究

三浦悠佑, 石黒雄一, 永井大樹, 浅井圭介, 佐宗章弘

衝撃波シンポジウム講演論文集　2005　71-72　2006/03/16
Cryogenic infrared mission "jAXA/SPICA" with advanced cryocoolers Peer-reviewed

Hiroyuki Sugita, Takao Nakagawa, Hiroshi Murakami, Atsushi Okamoto, Hiroki Nagai, Masahide Murakami, Katsuhiro Narasaki, Masayuki Hirabayashi

Cryogenics　46　(2-3)　149-157　2006/02

DOI： 10.1016/j.cryogenics.2005.11.017 　

ISSN： 0011-2275
Molecular sensors in microturbine measurement Peer-reviewed

Chihyung Huang, James W. Gregory, Hiroki Nagai, Keisuke Asai, John P. Sullivan

American Society of Mechanical Engineers, Micro-Electro Mechanical Systems Division, (Publications) MEMS　2006

DOI： 10.1115/IMECE2006-13814 　

ISSN： 1096-665X
PSP measurement of pressure distribution in a supersonic micronozzle Peer-reviewed

H. Nagai, R. Naraoka, K. Sawada, K. Asai

Collection of Technical Papers - 44th AIAA Aerospace Sciences Meeting　17　12552-12561　2006
Effect of TSP layer thickness on global heat transfer measurement in hypersonic flow Peer-reviewed

Shunsuke Ohmi, Hiroki Nagai, Keisuke Asai, Kazuyuki Nakakita

Collection of Technical Papers - 44th AIAA Aerospace Sciences Meeting　17　12570-12583　2006
Application of lifetime PSP imaging method to a cryogenic wind tunnel Peer-reviewed

Toshiyuki Kojima, Hiroki Nagai, Keisuke Asai, Kazunori Mitsuo, Yoshimi Iijima, Hirotaka Sakaue

Collection of Technical Papers - 44th AIAA Aerospace Sciences Meeting　17　12527-12540　2006
Flow Field Measurement of a Simplified Car Model using Pressure-Sensitive Paint

杉浦光, 山下太郎, 永井大樹, 浅井圭介, 石田圭太郎

日本機械学会流体工学部門講演会講演論文集(CD-ROM)　84th　ROMBUNNO.G303　2006

ISSN： 1348-2882
微小流動研究のためのマイクロ超音速風洞の開発

倉科大輔, 永井大樹, 浅井圭介

日本航空宇宙学会北部支部講演会講演論文集　2006　95-96　2006
Measurement of oxygen partial pressure distribution in a fuel cell using Pressure-Sensitive Paint

稲垣俊, 永井大樹, 浅井圭介

日本機械学会流体工学部門講演会講演論文集(CD-ROM)　84th　ROMBUNNO.G302　2006

ISSN： 1348-2882
感圧塗料による燃料電池内の酸素分圧分布測定

稲垣俊, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(06-017(CD-ROM))　ROMBUNNO.2 1　2006

ISSN： 1349-113X
金属ポルフィリンを連結した酸素透過性ポリマー膜の感圧特性

小幡誠, 松浦徳子, 矢野重信, 満尾和徳, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(06-017(CD-ROM))　ROMBUNNO.2 8　2006

ISSN： 1349-113X
デルタ翼Wing Rock現象の非定常可視化実験

廣瀬悠一, 永井大樹, 浅井圭介

日本航空宇宙学会北部支部講演会講演論文集　2006　85-90　2006
マイクロスケールデバイス周りの流れ場診断技術

倉科大輔, 奈良岡亮太, 永井大樹, 浅井圭介

宇宙航空研究開発機構特別資料 JAXA-SP-　(06-017(CD-ROM))　ROMBUNNO.2 2　2006

ISSN： 1349-113X
超音速マイクロノズルの気流診断技術に関する研究

奈良岡亮太, 永井大樹, 浅井圭介

日本航空宇宙学会北部支部講演会講演論文集　2006　91-94　2006
PSP Measurement of the Flow around a Simplified Car Model

Yamashita Taro, Sugiura Hikaru, Nagai Hiroki, Asai Keisuke, Ishida Keitaro

Journal of the Visualization Society of Japan　26　(1)　197-200　2006
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.26.Supplement1_197 　

ISSN： 0916-4731

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In applying Pressure-Sensitive Paint (PSP) to low-speed wind tunnel testing, it is important to minimize the measurement uncertainties. There are various noise sources such as camera noise, misalignment of images due to model displacement, and temperature distribution over a model. Among these factors, we studied the effects of temperature distribution change during tests on pressure measurement accuracy. Pressure and temperature distributions over a simplified car model (Ahmed model) were measured using biluminophore paint. Sequential images were acquired at the same interval over the entire test period including the conditions before or after the tunnel run. As a result, it was found that, the most accurate result was obtained by ratioing wind-on image with the wind-off image having similar temperature distribution. In these cases, we could correct the effect of temperature distribution using a single-point measurement of model surface temperature.
G302 Measurement of oxyecoia pressure distribution in a fuel cell using pressure sensitive paint(1)

Inagaki Suguru, Nagai Hiroki, Asai Keisuke

The Proceedings of the Fluids engineering conference　2006　(0)　_G302-a_　2006
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmefed.2006._G302-a_ 　

ISSN： 1348-2882
G302 Measurement of oxygen partial pressure distribution in a fuel cell using Pressure-Sensitive Paint(2)

Inagaki Suguru, Nagai Hiroki, Asai Keisuke

The Proceedings of the Fluids engineering conference　2006　(0)　_G302-1_-_G302-4_　2006
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmefed.2006._G302-1_ 　

ISSN： 1348-2882

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To improve efficiency and service life of a fuel cell, it is important to understand dynamic behavior of oxygen molecules in the cell. In other words, we need to know oxygen concentration distribution over electrode planes and inside diffused layers and its time variation. We applied Pressure-Sensitive Paint technique to this problem, attempting to measure distribution of partial pressure of oxygen along micro channels of a fuel cell. To prevent the effect of water produced by power generation process, we developed a water-repellant PSP that can withstand heat and humidity produced by power generation. Using this paint, partial oxygen distributions along the micro channels were successfully visualized, although there were noticeable effects of local temperature distribution on the absolute accuracy for the conditions with higher current densities.
G303 Flow Field Measurement of a Simplified Car Model using Pressure-Sensitive Paint(1)

SUGIURA Hikaru, YAMASHITA Taro, NAGAI Hiroki, ASAI Keisuke, ISHIDA Keitaro

The Proceedings of the Fluids engineering conference　2006　(0)　_G303-a_　2006
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmefed.2006._G303-a_ 　

ISSN： 1348-2882
G303 Flow Field Measurement of a Simplified Car Model using Pressure-Sensitive Paint(2)

SUGIURA Hikaru, YAMASHITA Taro, NAGAI Hiroki, ASAI Keisuke, ISHIDA Keitaro

The Proceedings of the Fluids engineering conference　2006　(0)　_G303-1_-_G303-4_　2006
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmefed.2006._G303-1_ 　

ISSN： 1348-2882

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Yawing moment and side force affect behavior of an automobile in crosswind. In wind tunnel testing, these aerodynamic forces are usually measured using a strain-gage balance. However, using Pressure-Sensitive Paint (PSP), we can measure surface pressure and obtain the force acting on each surface. In the present study, pressure distribution on top and four side surfaces of a simplified car model (1/10 scale Ahmed model) was measured using PSP at yaw angle ψ= 0 and 20[deg]. As a result, we could correlate the negative pressure regions appeared in the PSP images with separated regions and vortices shown in oil flow. In the case of ψ= 20[deg], it was shown that pressure difference between the leeward side and the windward side produced unstable yawing moment.
Effect of Temperature-Sensitive Paint Layer on Global Heat Transfer Measurement in Hypersonic Flow

NAGAI Hiroki, OHMI Shunsuke, ASAI Keisuke, NAKAKITA Kazuyuki

Journal of the Visualization Society of Japan　26　(1)　201-204　2006
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.26.Supplement1_201 　

ISSN： 0916-4731

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Heat flux measurement in a hypersonic wind tunnel is one of indispensable requirements for designing the next generation re-entry vehicle. Heat flux is usually calculated from a temporal change in temperature on the model surface. Temperature-Sensitive Paint (TSP) is a global temperature measurement technique based on photochemical reaction. This technique was applied to a hypersonic shock tunnel test, but there existed uncertainties caused by TSP layer thickness. In this study, the relationship between TSP layer thickness and measurement accuracy in heat flux was investigated by experiment. The models were tested at Mach 10 in the JAXA 0.44-m Hypersonic Shock Tunnel and heat flux caused by aerodynamic heating on the model surface was measured. A comparison between TSP data and conventional thermocouple data showed that the measurement error changed with the layer thickness in nonlinear fashion. To demonstrate the capability of TSP with the optimized thickness, tests using a 3-dimensional wing-body model have been conducted and the complicated heat flux pattern caused by shock-wave/shock-wave interaction has been observed.
PSP measurement of Pressure Distribution in a Supersonic Micronozzle

永井大樹, 奈良岡亮太, 浅井圭介

可視化情報学会誌　25　(Suppl.1)　331-332　2005/07/01

DOI： 10.3154/jvs.25.Supplement1_331 　

ISSN： 0916-4731
Application of Lifetime PSP Imaging Method to a Cryogenic Wind Tunnel

KOJIMA Toshiyuki, NAGAI Hiroki, ASAI Keisuke, MITSUO Kazunori, IIJIMA Yoshimi, SAKAUE Hirotaka

Journal of the Visualization Society of Japan　25　(1)　339-342　2005/03/15
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.25.Supplement1_339 　

ISSN： 0916-4731

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The intensity-based method is a most common technique by which Pressure-Sensitive Paint images can be converted to the surface pressure. However, this method cannot be applied to a cryogenic wind tunnel because the thermal equilibrium condition cannot be achieved when stopping the tunnel to take the wind-off reference image. In the present experiment, we applied the lifetime-based method to a cryogenic wind tunnel to calculate surface pressure from two images obtained during the wind-on condition. In this experiment, the circular-arc bump model sprayed with PtTFPP/PTMSP paint was tested at the JAXA 0.1m Cryogenic Transonic Wind Tunnel using a UV-LED pulse illuminator and a multi-gated CCD camera. As a result, we could succeed in visualizing surface pressure distribution induced by a shock wave on the model by using lifetime PSP imaging method. This result has demonstrated a feasibility of using lifetime imaging method to a cryogenic wind tunnel.
PSP measurement of Pressure Distribution in a Supersonic Micronozzle

NAGAI Hiroki, NARAOKA Ryota, ASAI Keisuke

可視化情報学会誌. Suppl.　25　(1)　331-332　2005/03/15

ISSN： 0916-4731
Application of Lifetime PSP Imaging Method to a Cryogenic Wind Tunnel

KOJIMA Toshiyuki, NAGAI Hiroki, ASAI Keisuke, MITSUO Kazunori, IIJIMA Yoshimi, SAKAUE Hirotaka

Journal of the Visualization Society of Japan　25　(1)　339-342　2005/03/15
Publisher: 社団法人可視化情報学会
ISSN： 0916-4731

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The intensity-based method is a most common technique by which Pressure-Sensitive Paint images can be converted to the surface pressure. However, this method cannot be applied to a cryogenic wind tunnel because the thermal equilibrium condition cannot be achieved when stopping the tunnel to take the wind-off reference image. In the present experiment, we applied the lifetime-based method to a cryogenic wind tunnel to calculate surface pressure from two images obtained during the wind-on condition. In this experiment, the circular-arc bump model sprayed with PtTFPP/PTMSP paint was tested at the JAXA 0.1m Cryogenic Transonic Wind Tunnel using a UV-LED pulse illuminator and a multi-gated CCD camera. As a result, we could succeed in visualizing surface pressure distribution induced by a shock wave on the model by using lifetime PSP imaging method. This result has demonstrated a feasibility of using lifetime imaging method to a cryogenic wind tunnel.
Effect of TSP Layer Thickness on Global Heat Transfer Measurement in a Hypersonic Shock Tunnel

OHMI Shunsuke, NAGAI Hiroki, ASAI Keisuke, NAKAKITA Kazuyuki

Journal of the Visualization Society of Japan　25　(1)　343-346　2005/03/15
Publisher: 可視化情報学会
ISSN： 0916-4731
新世代ヒートパイプLoop Heat Pipe

上野史郎, 永井大樹

宇宙科学シンポジウム　5　509-512　2005/01/06
Publisher: 宇宙科学研究所
Innovative cryogenic system for Japanese infrared astronomical mission "spica" Peer-reviewed

Hiroyuki Sugita, Takao Nakagawa, Hiroshi Murakami, Toshio Matsumoto, Hiroki Nagai, Masahide Murakami, Katsuhiro Narasaki, Masayuki Hirabayashi

International Astronautical Federation - 56th International Astronautical Congress 2005　1　633-641　2005
Thermal performance verification for the JEM MAXI loop heat pipe and radiator system Peer-reviewed

Hiroki Nagai, Shiro Ueno

International Astronautical Federation - 56th International Astronautical Congress 2005　3　1913-1920　2005
Start-up behavior of double-condenser loop heat pipe Peer-reviewed

H. Nagai, M. Muto, M. Murakami, S. Ueno

38th AIAA Thermophysics Conference　2005
Performance evaluation of double-condenser loop heat pipe onboard monitor of all-sky x-ray image (MAXI) in thermal vacuum testing

Hiroki Nagai, Shiro Ueno

SAE Technical Papers　2005

DOI： 10.4271/2005-01-2939 　
Design of Cryogenic System for Next Space Infrared Mission "SPICA"

杉田寛之, 岡本篤, 中川貴雄, 村上浩, 永井大樹, 村上正秀, 楢崎勝弘, 平林誠之

宇宙科学技術連合講演会講演集(CD-ROM)　49th　2G04　2005

ISSN： 1884-1945
Start-up Behavior of Double-condenser design Loop Heat Pipe for MAXI

永井大樹, 武藤美樹, 村上正秀, 上野史郎

宇宙科学技術連合講演会講演集(CD-ROM)　49th　1E01　2005

ISSN： 1884-1945
11-26-53C11-06 体育授業が生徒にどの様な学習効果をあたえるか : 「模擬授業」の実践が体育・教育系大学進学を目指す高校生の意識に与える影響(11 体育科教育,一般研究発表)

永島昇太郎, 永井大樹, 本間啓二

日本体育学会大会予稿集　56　(0)　396-396　2005
Publisher: 一般社団法人日本体育学会
DOI： 10.20693/jspehss.56.396_3 　
PSP measurement of Pressure Distribution in a Supersonic Micronozzle

NAGAI Hiroki, NARAOKA Ryota, ASAI Keisuke

Journal of the Visualization Society of Japan　25　(1)　331-332　2005
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.25.Supplement1_331 　

ISSN： 0916-4731

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In recent years, the interest in microdevices and systems has increased rapidly. Gaseous flow through and within such devices is a principal consideration in many applications, and its understanding can be crucial for optimization of performance. Most of the sensors applied to MEMS devices measurement have limited resolution restricted by the sensor size and device geometry. Pressure-sensitive paint (PSP) is one of the options for global distribution measurement in MEMS devices. PSP is a "molecular sensor, " and has an enough resolution for MEMS. In this paper, we demonstrate the use of PSP for quantitative measurement of pressure distribution in a supersonic micronozzle of the nozzle throat 250μm, such as those that might be employed for flow control and/or small satellite orbit maintenance.
Effect of TSP Layer Thickness on Global Heat Transfer Measurement in a Hypersonic Shock Tunnel

Ohmi Shunsuke, Nagai Hiroki, Asai Keisuke, Nakakita Kazuyuki

Journal of the Visualization Society of Japan　25　(1)　343-346　2005
Publisher: The Visualization Society of Japan
DOI： 10.3154/jvs.25.Supplement1_343 　

ISSN： 0916-4731

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Heat flux measurement in a wind tunnel is an indispensable requirement for the next generation re-entry vehicle design. Heat flux is usually calculated from a temporal change in surface temperature. Temperature-Sensitive Paint (TSP) is a global temperature measurement technique based on photochemical reaction. This technique has been already applied to a hypersonic shock tunnel, but poses some problems caused by TSP layer thickness. In this paper, the relationship between TSP layer thickness and measurement accuracy in heat flux was studied systematically. A test model is made of engineering ceramic, which coated with TSP composed of Ru(phen)³⁺ as luminophore and polyacrylic acid as binder. The layer thickness was varied from 1 to 9 micro meters. Wind tunnel tests were conducted in the JAXA 0.44-m Hypersonic Shock Tunnel. The model was tested in Mach 10 hypersonic flow and heat flux caused by aerodynamic heating was measured. A comparison between TSP data and conventional thermocouple data showed that the relationship between the layer thickness and the temperature error is not a simple liner relationship predicted by the theory. The deviation from the theory is significant particularly for the cases with very thin coatings.
振動流型ヒートパイプの中性子ラジオグラフィによる可視化実験

遠山伸一, 二俣亮介, 永井大樹, 松林政仁

日本原子力研究所JAERI-Review　379-380　2004/08
超流動ヘリウム中の衝撃波によって誘起される熱流体現象の研究

二谷有香, 村上正秀, 永井大樹

衝撃波シンポジウム講演論文集　2003　199-200　2004/03/18
次期赤外線天文衛星SPICAの冷却系開発

杉田寛之, 永井大樹, 中川貴雄

宇宙科学シンポジウム　4　295-298　2004/01/08
Publisher: 宇宙科学研究所
JEM/MAXI冷却システム用ループヒートパイプの評価試験

永井大樹, 上野史郎, 松岡勝

宇宙科学シンポジウム　4　511-514　2004/01/08
Publisher: 宇宙科学研究所
Space cryogenic system for SPICA mission Peer-reviewed

Hiroyuki Sugita, Hiroki Nagai, Takao Nakagawa, Hiroshi Murakami, Toshio Matsumoto, Masahide Murakami, Katsuhiro Narasaki, Masayuki Hirabayashi

Proceedings of SPIE - The International Society for Optical Engineering　5487　(PART 3)　1625-1633　2004

DOI： 10.1117/12.551173 　

ISSN： 0277-786X
全天X線監視装置(MAXI)開発の現状

森井幹雄, 松岡勝, 上野史郎, 冨田洋, 磯部直樹, 片山晴善, 横田孝夫, 倉又尚之, 永井大樹, 三原建弘, 小浜光洋, 桜井郁也, 常深博, 宮田恵美, 河合誠之, 片岡淳, 吉田篤正, 山岡和貴, 根来均

日本天文学会年会講演予稿集　2004　256　2004

ISSN： 1347-0639
Visualization study for Oscillating Heat Pipe by using neutron radiography

遠山伸一, 二俣亮介, 永井大樹, 岡本篤, 松林政仁

宇宙科学技術連合講演会講演集(CD-ROM)　47th　343-345　2003/11/17

ISSN： 1884-1945
Thermal Performance Test of Oscillating Heat Pipe

岡本篤, 二俣亮介, 永井大樹, 遠山伸一

宇宙科学技術連合講演会講演集(CD-ROM)　47th　346-350　2003/11/17

ISSN： 1884-1945
Design analysis and Development of Loop Heat Pipe

永井大樹

宇宙科学技術連合講演会講演集(CD-ROM)　47th　339-342　2003/11/17

ISSN： 1884-1945
ヘリウム中の衝撃波による熱流動現象に関する実験的研究

二谷有香, 谷中一喜, 永井大樹, 村上正秀

低温工学・超電導学会講演概要集　68th　64　2003/05/21

ISSN： 0919-5998
The Experimental Study of Thermo-Fluid Dynamic Phenomena caused by Shock Waves in Liquid Helium

FUTAYA Yuka, YANAKA Kazuyoshi, NAGAI Hiroki, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　68　64-64　2003/05/21

ISSN： 0919-5998
The performance test of the loop heat pipe and radiator system for cooling the CCD camera on board Monitor of All sky X-ray Image

永井大樹, 上野史郎, 富田洋, 磯部直樹, 松岡勝

宇宙ステーション講演会,有人宇宙飛行技術シンポジウム講演集　19th-16th　43-44　2003/04/25
He II中を伝播する衝撃波背後の圧力変動

二谷有香, 谷中一喜, 永井大樹, 村上正秀

衝撃波シンポジウム講演論文集　2002　155-158　2003/03/13
全天X線監視装置(MAXI)搭載CCDカメラ冷却用ループヒートパイプ(LHP)の伝熱特性に関する地上実験

永井大樹, 上野史郎, 松岡勝

宇宙科学シンポジウム　3　353-356　2003/01/09
Publisher: 宇宙科学研究所
Steady and transient behavior of a double-condenser design LHP for MAXI Peer-reviewed

Hiroki Nagai, Miki Muto, Masahide Murakami, Shiro Ueno, Masaru Matsuoka

36th AIAA Thermophysics Conference　2003
Ground experiment on heat transfer characteristic of Loop Heat Pipe (LHP) for the Monitor of All- sky X-ray Image (MAXI) installation CCD camera cooling.

永井大樹, 武藤美希, 村上正秀, 上野史郎, 松岡勝

宇宙科学シンポジウム平成14年度第3回　353-356　2003
Ground experiment on heat transfer characteristics of a loop heat pipe (LHP) for MAXI cooling system to be installed on ISS.

永井大樹, 武藤美希, 村上正秀, 上野史郎, 松岡勝

宇宙航行の力学シンポジウム平成14年度　147-150　2003
衝撃圧縮により誘起されるHe II‐He I間のλ‐相転移

谷中一喜, 上田康裕, 村上正秀, 永井大樹, YANG H S

低温工学・超電導学会講演概要集　66th　41　2002/05/18

ISSN： 0919-5998
He II-to-He I λ-Phase Transition Induced by Shock Compression

YANAKA Kazuyoshi, UETA Yasuhiro, MURAKAMI Masahide, NAGAI Hiroki, YANG HyungSuk

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　66　41-41　2002/05/18

ISSN： 0919-5998
Ground Experiment on Loop Heat Pipe for Monitor of All-sky X-ray Image. (2).

永井大樹, 武藤美希, 村上正秀, 上野史郎, 松岡勝

宇宙ステーション講演会,有人宇宙飛行技術シンポジウム講演集　18th-15th　15-16　2002/04/25
衝撃圧縮によって誘起されるHe II‐He I間のλ‐相転移に関する温度測定

上田康裕, 谷中一喜, 村上正秀, 永井大樹, YANG H S

衝撃波シンポジウム講演論文集　2001　645-648　2002/03/14
Thermal behavior of a double-condenser design LHP for Monitor of All-sky X-ray Image

Miki Muto, Masahide Murakami, Hiroki Nagai, Shiro Ueno, Masaru Matsuoka

SAE Technical Papers　2002

DOI： 10.4271/2002-01-2505 　
Transient and Start-up Behavior of Loop Heat Pipe due to Gravity for MAXI System

永井大樹, 武藤美希, 村上正秀, 上野史郎, 松岡勝

宇宙科学技術連合講演会講演集　46th　(Pt.3)　864-867　2002
Thermal Analysis and Evaluation for MDS-1 in orbit

永井大樹, 二俣亮介

宇宙科学技術連合講演会講演集　46th　(Pt.3)　1041-1046　2002
Thermal Performance on LHP for Monitor of All-sky X-ray Image-(1)

武藤美希, 村上正秀, 永井大樹, 上野史郎, 松岡勝

宇宙科学技術連合講演会講演集　46th　(Pt.3)　858-863　2002
Design and Development of Miniature and Lightweight Loop Heat Pipe for Spacecraft Thermal Control

永井大樹, 望月正孝, 川原洋司

宇宙科学技術連合講演会講演集　46th　(Pt.3)　868-872　2002
Thermal Analysis and Predictive Accuracy by using CAD System

永井大樹, 二俣亮介

Proceedings of the Annual Conference of the Japan Society for Industrial and Applied Mathematics　2002　(0)　172-172　2002
Publisher: The Japan Society for Industrial and Applied Mathematics
DOI： 10.11540/pjsiam.2002.0.172.0 　

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衛星の熱解析を行う際に、解析の対象物が大きくなったり複雑になったりすると、解析で用いる熱数学モデルの作成に多大な時間と労力が必要となる。従って、熱解析を効率よく、短時間に行うためにCADシステムを導入した解析手法が取られるようになっている。これにより、形状モデルの作成や変更に対して素早く対応することが可能となっている。本講演では、このCADシステムを利用した衛星熱設計手法と予測精度に関して、今年２月に打ち上げられたH2A２号機に搭載された実証衛星MDS-1を例として話をする。
Ground Experiment on Loop Heat Pipe for Monitor of All-sky X-ray Image.

武藤美希, 村上正秀, 永井大樹, 上野史郎, 松岡勝

宇宙科学技術連合講演会講演集　45th　1303-1308　2001/10/17
Propagation of a compression shock wave in He II induced by shock impingement

MURAKAMI Masahide, UETA Yasuhiro, YANAKA Kazuyoshi, NAGAI Hiroki, YANG HungSuk

日本流体力学会年会講演論文集 = Proceedings, ... meeting of Japan Society of Fluid Mechanics　2001　577-578　2001/07/01
Publisher: 日本流体力学会
ISSN： 1342-8004

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The propagation of a compression shock wave in superfluid helium (He II) was experimentally investigated by using the superfluid shock tube facility. A shock wave is generated in He II by the impingement of a gas dynamic shock wave onto vapor-He II interface. In fact, upon the impingement two modes of shock waves, a compression and a thermal shock waves, are induced in He II. Here, we are only interested in the former. One of our research target is the shock-compressed phase transition (He II to He I). The λ-phase transition is successfully caused in such a very rapid process as shock wave compression. The shock wave propagation properties are measured by piezo-type pressure transducers and in-house-made superconductive temperature sensors. Schlieren visualization method is also adopted with an ultra-high-speed video recorder (40,500 pictures/s).
Application of the superfluid shock tube facility to the study of ultra-high Reynolds number flow

YANAKA Kazuyoshi, YANG HyungSuk, UETA Yasuhiro, NAGAI Hiroki, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　64　152-152　2001/05/16

ISSN： 0919-5998
Start Up and Static Performance of Onboard Loop Heat Pipe for All Sky Xray Image Monitor

永井大樹, 武藤美希, 村上正秀, 上野史郎, 松岡勝

宇宙ステーション講演会,有人宇宙飛行技術シンポジウム講演集　17th-14th　51-52　2001/04/19
衝撃波背後に誘起されたHe II流れの高レイノルズ流れ実験への応用

上田康裕, 永井大樹, YANG H S, 谷中一喜, 村上正秀

衝撃波シンポジウム講演論文集　2000　109-112　2001/03/08
衝撃圧縮により誘起されるHe IIの高度に非定常な相転移現象の研究

永井大樹, YANG H S, 上田康裕, 谷中一喜, 村上正秀

衝撃波シンポジウム講演論文集　2000　125-128　2001/03/08
微小重力下における液量計測技術に関する研究

中納暁洋, 武藤美希, 藤山純一, 永井大樹, 村上正秀

日本マイクログラビティ応用学会誌　18　(4)　263-268　2001

ISSN： 0915-3616
Experimental Study of He II-He I Lambda-transition induced by shock compression

NAGAI Hiroki, YANG HyungSuk, UETA Yasuhiro, SATOU Ryuuji, MURAKAMI Masahide, YANAKA Kazuyoshi

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　63　54-54　2000/10/31

ISSN： 0919-5998
Generation and Development of The Thermal Boundary Layer near Shock-Compressed He II-Vapor Interface

UETA Yasuhiro, YANG HyungSuk, NAGAI Hiroki, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　63　55-55　2000/10/31

ISSN： 0919-5998
衝撃波圧縮による超流動ヘリウムのラムダ相転移

永井大樹, YANG H S, 上田康裕, 村上正秀

衝撃波シンポジウム講演論文集　1999　477-480　2000/03/16
Thermal Shock Wave induced by a Gasdynamic Shock Wave Impingement to He II Free Surface

YANG HyungSuk, NAGAI Hiroki, UETA Yasuhiro, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　61　237-237　1999/11/10

ISSN： 0919-5998
衝撃圧縮によるHe IIの非定常相変化

永井大樹, 高野奈穂子, YANG H S, 村上正秀

低温工学・超電導学会講演概要集　60th　274　1999/06/07

ISSN： 0919-5998
Transient Phase Change of He II induced by Shock Compression

NAGAI Hiroki, TAKANO Nahoko, YANG HyungSuk, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　60　274-274　1999/06/07

ISSN： 0919-5998
超流動ヘリウム中の衝撃波によって誘起された温度変化

YANG H S, 永井大樹, 高野奈穂子, 村上正秀

衝撃波シンポジウム講演論文集　1998　317-320　1999/03/19
衝撃波の自由界面入射により誘起される超流動ヘリウム中の衝撃波および非定常相変化の研究

永井大樹, YANG H S, 高野奈穂子, 村上正秀

衝撃波シンポジウム講演論文集　1998　321-324　1999/03/19
Characteristics of propagating shock waves in He II

NAGAI Hiroki, YANG HyungSuk, TAKANO Nahoko, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　58　228-228　1998/05/20

ISSN： 0919-5998
Temperature Variation caused by Shock Waves in He II

YANG HyungSuk, NAGAI Hiroki, TAKANO Nahoko, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　58　229-229　1998/05/20

ISSN： 0919-5998
Temperature Variation caused by Shock Waves in He II.

YANG H, 永井大樹, 高野奈穂子, 村上正秀

低温工学・超電導学会講演概要集　58th　229　1998/05

ISSN： 0919-5998
Characteristics of propagating shock waves in He II.

永井大樹, YANG H S, 高野奈穂子, 村上正秀

低温工学・超電導学会講演概要集　58th　228　1998/05

ISSN： 0919-5998
Two modes of shock waves caused by impinging a gas dynamic shock wave on the He II free surface.

永井大樹, YANG H S, 高野奈穂子, 村上正秀

衝撃波シンポジウム講演論文集　1997　575-578　1998/03
Study of phase transition induced in He II by shock wave.

高野奈穂子, 永井大樹, YANG H, 村上正秀

衝撃波シンポジウム講演論文集　1997　369-372　1998/03
Investigation of shock waves in superfluid helium.

永井大樹, 高野奈穂子, YANG H S, 村上正秀

流体力学講演会講演集　30th　1-4　1998
Development of Superfluid Shock Tube Facility

NAGAI Hiroki, YANG HyungSuk, TAKANO Nahoko, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　57　146-146　1997/11/18

ISSN： 0919-5998
Investigation of wave motion phenomena in superfluid helium by a gas dynamic shock wave incidence

YANG HyungSuk, NAGAI Hiroki, TAKANO Nahoko, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　57　147-147　1997/11/18

ISSN： 0919-5998
Development of Superfluid Shock Tube Facility.

永井大樹, YANG H S, 高野奈穂子, 村上正秀

低温工学・超電導学会講演概要集　57th　146　1997/11

ISSN： 0919-5998
Invesitigation of wave motion phenomena in superfluid helium by a gas dynamic shock wave incidence.

YANG H S, 永井大樹, 高野奈穂子, 村上正秀

低温工学・超電導学会講演概要集　57th　147　1997/11

ISSN： 0919-5998
超流動ヘリウム気液自由界面における第2音波の反射

古川徹, 村上正秀, 永井大樹

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　55　250-250　1996/11/06

ISSN： 0919-5998
Reflection of second sound at free interface of vapor-liquid of superfluiditive helium.

古川徹, 村上正秀, 永井大樹

低温工学・超電導学会講演概要集　55th　250　1996/11

ISSN： 0919-5998
レーザーホログラフィー干渉計有限干渉縞法によるHe II中の熱流体現象の可視化

飯田光人, 村上正秀, 島崎毅, 永井大樹

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　53　121-121　1995/05/17

ISSN： 0919-5998
レーザーホログラフィー干渉計有限干渉縞法によるHe II中の熱流体現象の可視化

飯倒光人, 村上正秀, 島崎毅, 永井大樹

低温工学・超電導学会講演概要集　53rd　121　1995/05

ISSN： 0919-5998

Show all ︎Show first 5

Books and Other Publications 5

電子機器の放熱・冷却技術と部材の開発

技術情報協会

技術情報協会　2021/07

ISBN: 9784861048524
未利用熱エネルギー活用の新開発と【採算性を重視した】熱省エネ新素材・新製品設計／採用のポイント

永井大樹

株式会社技術情報協会　2014
Nano-mega Scale Flow Dynamics for Advanced Aerospace

Keisuke Asai, Hiroki Nagai

Tohoku University Press　2007
MEMS／NEMS工学大全

浅井圭介, 永井大樹

エヌティーエス株式会社　2007
機能性色素の合成と応用技術

浅井圭介, 永井大樹

シーエムシー出版　2007

Presentations 764

Development of Fast response Temperature Sensitive Paint and Its Application to Shock Tube

Jinyoung Kim, Mitha, Engin, Masaki Okawa, Bok, Jik Lee, Tsubasa Ikami, Hiroki Nagai

The 35th International Symposium on Shock Waves　2025/07/10
低速域でのデルタ翼ウイングロック現象の発現領域と動的不安定性の調査

山岸悠真, 伊神翼, 永井大樹

第57回流体力学講演会／第43回航空宇宙数値シミュレーション技術シンポジウム　2025/07/04
局在表面プラズモン共鳴を利用した感圧塗料の発光強度増幅

大川真生, 伊神翼, 渡辺花奈子, 永井大樹

第57回流体力学講演会／第43回航空宇宙数値シミュレーション技術シンポジウム　2025/07/03
導電性ポリマを用いた感温塗料の開発と評価

伊神翼, 永井大樹

第57回流体力学講演会／第43回航空宇宙数値シミュレーション技術シンポジウム　2025/07/03
Comparison of Oscillating Frequency on Flow Around an Oscillating Airfoil at Low Reynolds Number

Lim Gabriel Yiting, Okuizumi Hiroyuki, Okawa Masaki, Konishi Yasufumi, Ikami Tsubasa, Nagai Hiroki

2025/07/04
Data-Driven Approach for Combining Multiple Fields of View in Unsteady PIV Data

Haruka Kurahashi, Tsubasa Ikami, Hiroki, Nagai

ISPIV2025　2025/06/27
Investigation of Spanwise Velocity Variations along Wing Surface using Curved Laser Sheet PIV

Ritsuki Mise, Tsubasa Ikami, Hiroki Nagai

ISPIV2025　2025/06/26
非均ーな流路径による自励振動ヒートパイプの内部流動促進と高熱輸送性能化に向けた研究

川口歩夢, 永井大樹

第62回伝熱シンポジウム　2025/05/16
金属積層造形セカンダリーウィック形状がLHPの動作特性に与える影響

横内岳史, ロバーツスコット, 大丸拓郎, 永井大樹

第62回伝熱シンポジウム　2025/05/14
サバの尾びれを模倣した突起付き小型ロータの騒音評価

佐々木悠斗, 大塚光, 得竹浩, 佐々木大輔, 伊神翼, 永井大樹

日本航空宇宙学会第56期年会講演会　2025/04/04
進行率の異なるプロペラ後流中のNACA0012翼に対する数値解析による空力特性評価

佐藤颯斗, 大川真生, 伊神翼, 永井大樹, 北村圭一

日本航空宇宙学会第56期年会講演会　2025/04/04
超小型火星飛行機：膜翼を採用した収納・展開可能な超小型火星飛行機の概念検討（第二報）

工藤惣士, 河野日香, 髙木大成, 正木拓斗, 大島草太, 伊神翼, 永井大樹, 玉置義治, 今村太郎, 金崎雅博

日本航空宇宙学会第56期年会講演会　2025/04/04
超小型火星飛行機：超小型火星飛行機の低高度試験による機体成立性評価

鈴木悠吾, 木村梨花, 大川真生, 伊神翼, 永井大樹

日本航空宇宙学会第56期年会講演会　2025/04/04
火星探査航空機の研究開発：これまでとこれから

永井大樹

日本航空宇宙学会第56期年会講演会　2025/04/04
東北大学流体科学研究所における弾道飛行装置実験研究2

大谷清伸, 小川俊広, 永井大樹, 大林茂

2024年度衝撃波シンポジウム　2025/03/12
高速応答感圧塗料・感温塗料同時計測による衝撃波圧力・熱流束の高精度評価

大川真生, Jinyoung Kim, Mithat Engin, 伊神翼, 永井大樹

2024年度衝撃波シンポジウム　2025/03/12
高速応答性感温塗料の開発

Jinyoung Kim, Mithat Engin, 大川真生, 伊神翼, 永井大樹

2024年度衝撃波シンポジウム　2025/03/12
BOS法によるはやぶさ型カプセルまわりの定量的密度場計測

湊慎司, 山岸雅人, 井川将大, 猪狩優斗, 稲毛達朗, 太田匡則, 永井大樹

2024年度衝撃波シンポジウム　2025/03/12
弾道飛行装置を用いたはやぶさカプセル模型周りの4次元密度場計測

山岸雅人, 野木住隆, 堀尾大行, 宮崎龍汰, 廣瀬裕介, 稲毛達朗, 太田匡則, 大谷清伸, 永井大樹

2024年度衝撃波シンポジウム　2025/03/12
⾃励振動ヒートパイプの実験的研究加

加納歩輝, 川口歩夢, 伊神翼, 永井大樹

⽇本航空宇宙学会北部⽀部２０２５年講演会ならびに第６回再使⽤型宇宙輸送系シンポジウム　2025/03/11
感温塗料を⽤いたリブレット表⾯流れ場の可視化

伊藤夕樹, 伊神翼, 栗田充, 永井大樹

⽇本航空宇宙学会北部⽀部２０２５年講演会ならびに第６回再使⽤型宇宙輸送系シンポジウム　2025/03/10
Experimental Study of Flow around Oscillating Airfoil using cntTSP

Lim Gabriel Yiting, Ikami Tsubasa, Nagai Hiroki

2025/03/10
収納展開を考慮した柔軟構造による火星探査航空機の基礎検討

金崎雅博, 徳尾野陸, 工藤惣士, 永井大樹, 伊神翼, 玉置義治, 今村太郎

令和６年度航空宇宙空力シンポジウム　2025/01/24
火星飛行機に向けた高高度プロペラ性能評価試験(HIGHPER)

永井大樹, 大川真生, 三瀬律紀, 山下大智, 倉橋晴香, 伊神翼, 大塚光, 得竹浩, 大山聖

令和６年度航空宇宙空力シンポジウム　2025/01/24
自励振動ヒートパイプの数値モデリングとその応用 Invited

永井大樹

日本ヒートパイプ協会講演会　2024/12/12
Development of Polymer-Ceramic Pressure-Sensitive Paint Applicable in Wind Tunnel Experiments at Very Low Speed

Masaki Okawa, Yuma Yamagishi, Tsubasa Ikami, Kanako Watanabe, Hiroki Nagai

2024 Conference on Theoretical and Applied Mechanics (CTAM)　2024/11/30
Skin Friction Measurements for Rotating Blade in Low-Speed Condition by cntTSP

Tsubasa Ikami, Ren Nishimura, Hiroki Nagai

2024 Conference on Theoretical and Applied Mechanics (CTAM)　2024/11/30
Reliable Startup and Continuous Oscillation Conditions of OHP

Nagai Hiroki, Kawaguchi Ayumu

Joint 22nd International Heat Pipe Conference & 16th International Heat Pipe Symposium　2024/11/27
連成計算による膜翼上の翅脈状構造トポロジの空力性能と構造変形への影響

中井寛太, 永井大樹, 玉置義治, 今村太郎, 金崎雅博

第68回宇宙科学技術連合講演会　2024/11/08
展開式膜翼を用いたカナードを有する全翼機形状の超小型火星飛行機の概念検討

木村梨花, 大川真生, 伊神翼, 永井大樹

第68回宇宙科学技術連合講演会　2024/11/08
膜翼を採用した収納・展開可能な超小型火星飛行機の概念検討

工藤惣士, 髙木大成, 河野日香, 正木拓斗, 大島草太, 金崎雅博, 伊神翼, 永井大樹

第68回宇宙科学技術連合講演会　2024/11/08
火星飛行機に向けた高高度プロペラ性能評価試験(HIGHPER) - 結果速報 -

大川真生, 三瀬律紀, 山下大智, 倉橋晴香, 伊神翼, 永井大樹, 大塚光, 得竹浩, 大山聖

第68回宇宙科学技術連合講演会　2024/11/08
火星の飛行探査に関する研究開発

大山聖, 永井大樹

第68回宇宙科学技術連合講演会　2024/11/08
火星飛行機に向けた高高度プロペラ性能評価試験(HIGHPER)- 結果速報-

大川真生,三瀬律紀,山下大智,倉橋晴香,伊神翼,永井大樹,大塚光,得竹浩, 大山聖

大気球シンポジウム　2024/10/21
非定常サロゲートモデルによる宇宙機熱解析の不確かさの定量化

山下大智, 田中寛人, 伊神翼, 永井大樹

第37回計算力学講演会　2024/10/19
⽕星⾶⾏機の⾼⾼度⾶⾏試験(MABE-2)における空⼒特性の分析

金崎雅博, 藤田昂志, 安部明雄, 伊神翼, 大山聖, 永井大樹

第62 回⾶⾏機シンポジウム　2024/10/16
低レイノルズ数回転翼に生じる前縁剥離渦と空力特性の考察

伊神翼, 西村練, 永井大樹

日本流体力学会年会2024　2024/09/25
自励振動型ヒートパイプにおける逆止弁配置の熱輸送特性に関する実験的検証

川口歩夢, 笹岡佑全, 安藤麻紀子, 岡本篤, 伊神翼, 永井大樹

日本混相流学会混相流シンポジウム2024　2024/09/06
Experimental Study of Heat Transfer Characteristics of Oscillating Heat Pipe with Different Numbers and Orientations of Check Valves.

Ayumu Kawaguchi, Yuzen Sasaoka, Makiko Ando, Atsushi Okamoto, Tsubasa Ikami, Hiroki Nagai

THE 53RD INTERNATIONAL CONFERENCE ON ENVIRONMENTAL SYSTEMS　2024/07/24
Transient Surrogate Model using Recurrent Neural Networks for Spacecraft Thermal Analysis

Daichi Yamashita, Hiroto Tanaka, Tsubasa, Ikami.Hiroki Nagai

INTERNATIONAL CONFERENCE ON ENVIRONMENTAL SYSTEMS 2024　2024/07/24
ニューラルネットワークによる感圧塗料計測場のスパース予測

都木誠, 伊神翼, 江上泰広, 永井大樹, 柏川貴弘, 木村浩一, 松田佑

第52回可視化情報シンポジウム　2024/07/19
HighAltitudeFlight DemonstrationTest Report onMars AirplaneBalloonExperiment-2(MABE2)

Nagai,Hiroki, Oyama,Akira, Fujita,Koji, Kanazaki,Masahiro, Takano, Atsushi, Abe, Akio, Mitsutake, Katsushi, Tokutake, Hiroshi, Ikami,Tsubasa

COSPAR 2024　2024/07/15
揚力型再突入カプセルの亜音速域における動的不安定性の数値解析

岡野泰人, 佐藤慎太郎, 大西直文, 永井大樹

第56回流体力学講演会／第42回航空宇宙数値シミュレーション技術シンポジウム　2024/07/03
動的濡れモデルに基づく数値シミュレーションによる多孔質体内部の蒸発現象の解明

張展鵬, シェンビャオ, 金子暁子, 常新雨, 永井大樹

第 61 回⽇本伝熱シンポジウム・IWSEC2024　2024/05/30
火星飛行機の高高度飛行試験(MABE-2)の熱制御系について

永井大樹, 大山聖, 藤田昂志, 伊神翼, 金崎雅博, 安部明雄

日本航空宇宙学会第55期年会講演会　2024/04/18
火星飛行機の高高度飛行試験(MABE-2)の航法誘導制御系について

安部明雄, 大山聖, 永井大樹, 藤田昂志, 伊神翼, 金崎雅博

日本航空宇宙学会第55期年会講演会　2024/04/18
火星飛行機の高高度飛行試験(MABE-2)における空力特性について

金崎雅博, 藤田昂志, 安部明雄, 伊神翼, 大山聖, 永井大樹

日本航空宇宙学会第55期年会講演会　2024/04/18
火星飛行機の高高度飛行試験(MABE-2)の概要

大山聖, 永井大樹, 藤田昂志, 金崎雅博, 髙野敦, 安部明雄, 満武勝嗣, 得竹浩, 伊神翼

日本航空宇宙学会第55期年会講演会　2024/04/18
低レイノルズ数中領域でホバリングする回転翼の設計手法の提案とその評価

三瀬律紀, 西村練, 大川真生, 伊神翼, 永井大樹

第63回航空原動機・宇宙推進講演会/北部支部2024年講演会ならびに第5解再使用型宇宙輸送系シンポジウム　2024/03/15
低レイノルズ数中のプロペラ-固定翼系におけるプロペラ新効率と空力特性に関する研究

大川真生, 伊神翼, 永井大樹

第63回航空原動機・宇宙推進講演会/北部支部2024年講演会ならびに第5解再使用型宇宙輸送系シンポジウム　2024/03/15
データ駆動を用いた宇宙機熱設計解析の非定常サロゲートモデルの提案

山下大智, 伊神翼, 永井大樹

第63回航空原動機・宇宙推進講演会/北部支部2024年講演会ならびに第5解再使用型宇宙輸送系シンポジウム　2024/03/14
火星飛行機の第2回高高度飛行試験報告

永井大樹, 大山聖, 藤田昂志, 金崎雅博, 高野敦, 安部明雄

第63回航空原動機・宇宙推進講演会/北部支部2024年講演会ならびに第5解再使用型宇宙輸送系シンポジウム　2024/03/14
遷音速域における再突入カプセル模型まわりの非定常流れ場に対する定量密度計測

井川将大, 高坂菜央, 猪狩優斗, 山岸雅人, 太田匡則, 稲毛達朗, 川野理人, 大谷清伸, 永井大樹

2023年度衝撃波シンポジウム　2024/03/06
マイクロ秒以下の超高速応答性を持つAA-TSPの開発

阿部淳之介, 伊神翼, 永井大樹

2023年度衝撃波シンポジウム　2024/03/06
弾道飛行装置を用いたはやぶさカプセル模型周りの3次元密度場と模型迎角の同時計測

山岸雅人, 高坂菜央, 廣瀬裕介, 稲毛達朗, 宇田川真介, 太田匡則, 滝川侑弥, 大谷清伸, 永井大樹

年度衝撃波シンポジウム　2024/03/06
再突入型カプセルの超音速域における動的不安定性の数値解析

岡野泰人, 佐藤慎太郎, 大西直文, 永井大樹

2023年度衝撃波シンポジウム　2024/03/06
展開膜翼に対する空力-構造連成計算と超小型火星探査航空機翼設計への応用

金崎雅博, 中井寛太, 永井大樹, 伊神翼, 大山聖, 玉置義治, 今村太郎

令和5年度航空宇宙空力シンポジウム　2024/01/19
Mars Shot Plus -超小型火星飛行機による新しい探査手法の提案-

永井大樹

令和5年度航空宇宙空力シンポジウム　2024/01/19
第２回火星飛行機高高度飛行試験（MABE-2）の結果速報

大山聖, 永井大樹, 藤田昂志, 金崎雅博, 高野敦, 安部明雄, 満武勝嗣, 得竹浩, 伊神翼

令和5年度航空宇宙空力シンポジウム　2024/01/19
弾道飛行装置における３次元，４次元密度計測の現状について

太田匡則, 山岸雅人, 高坂菜央, 佐藤翔嬉, 野木住隆, 滝川侑弥, 大谷清伸, 永井大樹

令和5年度航空宇宙空力シンポジウム　2024/01/19
Dynamic Behavior Measurement of New Sample Return Capsule for Deep Space Exploration using Transonic Wind Tunnel

Rito Kawano, Tsubasa Ikami, Hiroki Nagai, Kazuhiko Yamada

AIAA SciTech Forum 2024　2024/01/11
Surface Flow Measurement in Low-Rotational-Speed Rotor using cntTSP

Ren Nishimura, Tsubasa Ikami, Hiroki Nagai

AIAA SciTech Forum 2024　2024/01/09
局在表面プラズモン共鳴を利用した超高輝度感圧塗料の設計

大川真生, 伊神翼, 渡部花奈子, 永井大樹

第19回学際領域における分子イメージングフォーラム　2023/12/22
AA-TSPの極低温二相流可視化計測への適応

横内岳史, 常新雨, 小田切公秀, 小川博之, 長野方星, 永井大樹

第19回学際領域における分子イメージングフォーラム　2023/12/22
PSP計測データのテンソル分解を利用した低ランク近似手法の開発

小久保琉史, 窪田航陽, 都木誠, 伊神翼, 江上泰広, 永井大樹, 松田佑

第19回学際領域における分子イメージングフォーラム　2023/12/22
cntTSPを用いた回転翼における表面摩擦応力場の計測

伊神翼, 西村練, 永井大樹

第19回学際領域における分子イメージングフォーラム　2023/12/22
同軸反転ロータの低Re数空力振動の数値解析

坂爪峻哉, 北村圭一, 西村練, 伊神翼, 永井大樹

第61回飛行機シンポジウム　2023/11/15
CLHPの凝縮現象解明に向けたあ極低温二相流の気液界面・温度分布同時計測手法の提案

横内岳史, 常新雨, 小田切公秀, 長野方星, 小川博之, 永井大樹

令和５年度宇宙航行の力学シンポジウム　2023/12/12
逆止弁が自励振動ヒートパイプの動作特性に与える影響（第ニ報：逆方向取り付け）

笹岡佑全, 川口歩夢, 安藤麻紀子, 岡本篤, 永井大樹

令和５年度宇宙航行の力学シンポジウム　2023/12/12
逆止弁が自励振動ヒートパイプの動作特性に与える影響（第一報：順方向取り付け）

川口歩夢, 笹岡佑全, 安藤麻紀子, 岡本篤, 永井大樹

令和５年度宇宙航行の力学シンポジウム　2023/12/12
新型大気圏再突入カプセルにおいて背面形状が動的特性に与える影響

川野理人, 伊神翼, 高橋幸一, 永井大樹, 山田和彦

令和５年度宇宙航行の力学シンポジウム　2023/12/11
揚力型再突入カプセルの超音速域における動的不安定性の数値解析

岡野泰人, 佐藤慎太郎, 大西直文, 永井大樹

令和５年度宇宙航行の力学シンポジウム　2023/12/11
火星飛行機におけるプロペラ進行率が固定翼の空力性能に与える影響の調査

大川真生, 伊神翼, 永井大樹

令和５年度宇宙航行の力学シンポジウム　2023/12/11
第２回火星飛行機高高度飛行試験（MABE-2）の結果報告

大山聖, 永井大樹, 藤田昂志, 金崎雅博, 高野敦, 安部明雄, 満武勝嗣, 得竹浩, 伊神翼

令和５年度宇宙航行の力学シンポジウム　2023/12/11
Three-deminsinal Density Measurement of Wake Region behind Re-entry Capsule Model to Clarify the Mechanism of its Dynamic Instability

Shoki Sato, Sumitaka Nogi, Nao Kosaka, Masato Yamagishi, Masanori Ota, Yota Hosono, Kiyonobu Ohtani, Hiroki Nagai

the Twenty-third International Symposium on Advanced Fluid Information　2023/11/07
Visualization of Leading Edge Vortex in Low Reynolds Number Rotor by cntTSP

Ren Nishimura, Tsubasa Ikami, Hiroki Nagai

Twentieth International Conference on Flow Dynamics　2023/11/06
Heat Transfer Limit Evaluation of Cryogenic Loop Heat Pipe

Takeshi Yokouchi, Xinyu Chang, Kimihide Odagiri, Hiroyuki Ogawa, Hosei Nagano, Hiroki Nagai

Twentieth International Conference on Flow Dynamics　2023/11/07
Visualization Study of Hysteresis Phenomena in a Multi-evaporator Loop Heat Pipe

Xinyu Chang, Noriyuki Watanabe, Hiroki Nagai, Hosei Nagano

Twentieth International Conference on Flow Dynamics　2023/11/07
火星飛行機の高高度飛行試験

大山聖, 永井大樹, 藤田昂志, 金崎雅博, 高野敦, 光武勝嗣, 得竹浩, 伊神翼

第32回スペース。エンジニアリング・コンファレンス　2023/11/24
頂点効果によるロータ推力変動の評価

赤羽峻瑛, 原大生, 大塚光, 得竹浩, 伊神翼, 永井大樹

第61回飛行機シンポジウム　2023/11/15
cntTSPを用いた低レイノルズ数中回転翼に生じる前縁剝離渦の可視化

西村練, 伊神翼, 永井大樹

第61回飛行機シンポジウム　2023/11/16
Study on Two-phase Thermo-fluid Phenomena in a 2-m Nitrogen Cryogenic Loop Heat Pipe

Kimihide Odagiri, Xinyu Chang, Takeshi Yokouchi, Atsuhiro, Hiroki Nagai, Hiroyuki Ogawa

the Twenty-third International Symposium on Advanced Fluid Information　2023/11/08
Aeroelastic Simulation Framework for Membrane Wings

Keisuke Otsuka, Shuonan Dong, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

the Twenty-third International Symposium on Advanced Fluid Information　2023/11/08
On the Reduction of the Flow-induced Noise using Bio-inspired Porus Material with Low Acoustic Transmission Loss

Naoyuki Takeda, Koki Shige, Osamu Terashima, Yasufumi Konishi, Tsubasa Ikami, Hiroki Nagai, Toshihiko Komatsuzaki

the Twenty-third International Symposium on Advanced Fluid Information　2023/11/07
Application of Post-Processing Method Using Digital Annealer tp PSP Measurement Data

Koyo Kubota, Tomoki Inoue, Tsubasa Ikami, Hiroki Nagai, Takahiro Kashigawa, Koichi Kimura, Yu Matsuda

the Twenty-third International Symposium on Advanced Fluid Information　2023/11/07
Computational and Experimental Study of Unsteady Flowfield around Flexible-membrane Wing at Low Reynolds Number toward Mars Airplane

Daisuke Sasaki, Kosei Funada, Koji Fujita, Yuki Kawamoto, Shun Takahashi, TsubasaIkami, Haruka Kurahashi, Hiroki Nagai

the Twenty-third International Symposium on Advanced Fluid Information　2023/11/07
Simulation of Fountain Flow Development in Quadrotor Wake with Smmetry Boundary Condition

Hikaru Otsuka, Taisei Hara, Hiroshi Tokutake, Hiroki Ngaai

the Twenty-third International Symposium on Advanced Fluid Information　2023/11/07
High-speed Plasma Flow Simulation on Spacecraft and Propulsion Systems

Masayuki Takahashi, Soichiro Suzuki, Hiroyuki Suzuki, Koki Ito, Hiroki Nagai

the Twenty-third International Symposium on Advanced Fluid Information　2023/11/07
Study on Combining Method of Time Series Flow Fields with Different Phases around Airfoil for Unsteady PIV

Haruka Kurahashi, Tsubasa Ikami, Hiroki Nagai

Twentieth International Conference on Flow Dynamics　2023/11/07
Influence of Propeller Wake on Mars Airplane Wing Geometry

Nana Hasegawa, Masahiro Kanazaki, Hiroki Nagai

Twentieth International Conference on Flow Dynamics　2023/11/07
Experimental Investigation on Dynamic Instability at Transonic Speeds of Thin-aeroshell Reentry Capsule

Rito Kawano, Tsubasa Ikami, Hiroki Nagai, Kazuhiko Yamada

Twentieth International Conference on Flow Dynamics　2023/11/07
Effects of Propeller Rotation Speed on Aerodynamic Performance of Wing in Tractor-Configuration

Masaki Okawa, Ren Nishimura, Haruka Kurahashi, Tsunasa Ikami, Hiroki Nagai

Twentieth International Conference on Flow Dynamics　2023/11/06
Sonic Boom Distribution Measurement of Supersonic Projectile in Ballistic Range

Junnosuke Abe, Toshiro Ogawa, Tsubasa Ikami, Hiroki Nagai, Shun Takahiashi

Twentieth International Conference on Flow Dynamics　2023/11/06
Development of Pressure Distribution Measurement Technique Using AA-PSP at Transonic Free-Flight

Yukiya Takikawa, Koichi Takahashi, Toshiro Ogawa, Tsubasa Ikami, Hiroki Nagai, Daiki Kurihiara, Joseph. P. Gonzales, Hirotaka Sakaue

Twentieth International Conference on Flow Dynamics　2023/11/06
Visualization of Low Mass Flux Nitrogen Condensate Flow Inside a Cryogenic Loop Heat Pipe

Atsuhiro Gomi, Kimihide Odagiri, Yuki Sakamoto, Shun Okazaki, Hiroki Nagai, Hiroyuki Ogawa

Twentieth International Conference on Flow Dynamics　2023/11/07
Numerical Analysis on the Heat Transport Performance of Oscillating Heat Pipe with Different Heating

Ayumu Kawaguchi, Takeshi Yokouchi, Makiko Ando, Tsubasa Ikami, Hiroki Nagai

Twentieth International Conference on Flow Dynamics　2023/11/07
Compressibility Effects around Propeller on Propeller-Wing Aerodynamic Interaction for Mars Airplane

Yoshikatsu Furusawa, Keiichi Kitamura, Tsubasa Ikami, Masaki Okawa, Hiroki Nagai

Twentieth International Conference on Flow Dynamics　2023/11/08
ゴム気球を用いた火星飛行機用プロペラの高高度試験（HIGHPER）

永井大樹

2023年度大気球シンポジウム　2023/10/23
新型カプセルにおける遷音速動的不安定性現象の形状依存性評価

川野理人, 伊神翼, 永井大樹, 山田和彦

第67回宇宙科学技術連合講演会　2023/10/18
ドローンからの自由落下による新型再突入カプセルの空力安定性評価

伊神翼, 川野理人, 永井大樹, 山田和彦

第67回宇宙科学技術連合講演会　2023/10/18
火星飛行機におけるプロペラ後流中の主翼翼型に対する影響調査

長谷川奈南, 金崎雅博, 永井大樹

第67回宇宙科学技術連合講演会　2023/10/17
火星ヘリコプタに学ぶ竹とんぼの設計手法の提案

伊神翼, 大川真生, 西村練, 永井大樹

第67回宇宙科学技術連合講演会　2023/10/17
ゴム気球を用いた火星飛行機用プロペラの高高度試験（HIGHPER）の概要と結果速報

大川真生, 三瀬律紀, 山下大智, 西村練, 伊神翼, 大塚光, 得竹浩, 大山聖, 永井大樹

第67回宇宙科学技術連合講演会　2023/10/17
火星の飛行探査に関する研究開発の現状

大山聖, 永井大樹

第67回宇宙科学技術連合講演会　2023/10/17
Japanese Mars Airplane-Creation of new vehicles for planetary exploration-

Hiroki Nagai

Joint Conference of APCATS, AJSAE & AAME 2023　2023/10/11
低レイノルズ数回転翼に生じる前縁剝離渦のcntTSPによる可視化ーアスペクト比の効果ー

伊神翼, 西村練, 永井大樹

日本流体力学会年会2023　2023/09/20
Ballistic Range Experiment for Space Exploration in Tohoku University

Hiroki Nagai, Kiyonobu Ohtani, Toshiro Ogawa

72nd Aeroballistic Range Association Meeting　2023/09/12
火星飛行の高高度飛行実証試験（MABE-2）の概要

永井大樹

航空宇宙流体科学サマースクール2023　2023/09/07
低乱風洞の改修について

永井大樹

東北大-JAXA連携協力(航空・流体科学系) 令和４年度共同研究報告会　2023/09/04
極低温における熱制御技術

永井大樹

東北大-JAXA連携協力(航空・流体科学系) 令和４年度共同研究報告会　2023/09/04
深宇宙サンプルリターン計画に向けた先進的サンプルリターンカプセル技術に関する研究

永井大樹

東北大-JAXA連携協力(航空・流体科学系) 令和４年度共同研究報告会　2023/09/04
Aerial Exploration using Mars Airplane

Hiroki Nagai

2023/08/28
極低温ループヒートパイプ内部における低質量流束窒素凝縮の可視観察

五味篤大, 小田切公秀, 坂本勇樹, 岡崎峻, 永井大樹, 小川博之

混相流シンポジウム2023　2023/08/24
充填圧の違いが極低温ループヒートパイプの温度振動に与える影響

横内岳史, 常新雨, 小田切公秀, 小川博之, 長野方星, 永井大樹

混相流シンポジウム2023　2023/08/24
加熱部配置が自励振動ヒートパイプの熱輸送特性に与える影響

川口歩夢, 横内岳史, 安藤麻紀子, 永井大樹

混相流シンポジウム2023　2023/08/24
逆止弁の向きが自励振動型ヒートパイプの動作特性に及ぼす影響

安藤麻紀子, 永井大樹

混相流シンポジウム2023　2023/08/24
周波数領域におけるPOD基底を用いた非定常PSPデータのノイズ低減

伊神翼, 永井大樹, 松田佑, 江上泰広

第51回可視化情報シンポジウム　2023/08/10
デジタルアニーラを用いた熱流動場のモデリング手法の提案

窪田航陽, 井上智輝, 伊神翼, 江上泰広, 永井大樹, 柏川貴弘, 木村浩一, 松田佑

第51回可視化情報シンポジウム　2023/08/10
非定常PIVによる翼周りの位相の異なる時系列流れ場の結合手法の提案

倉橋晴香, 伊神翼, 永井大樹

第51回可視化情報シンポジウム　2023/08/09
Development of Pressure Distribution Measurement Technique on Free-Flight Object Surface at Transonic Speed

Yukiya Takikawa, Yota Hosono, Toshiro Ogawa, Tsubasa Ikami, Hiroki Nagai, Joseph. P. Gonzales, Daiki Kurihara, Hirotaka Sakaue

The 34th International Symposium on Shock Wave　2023/07/18
Unsteady Force Measurement on Cylinder Surface Using Anodized Aluminum Pressure-Sensitive Paint

Junnosuke Abe, Shintaro Tamakuma, Toshiro Ogawa, Tsubasa Ikami, Hiroki Nagai, Shun Takahashi

The 34th International Symposium on Shock Wave　2023/07/21
Operating Characteristics of Cryogenic Loop Heat Pipes at Different Filling Pressures

Takeshi Yokouchi, Xinyu Chang, Kimihide Odagiri, Hiroyuki Ogawa, Hosei Nagano, Hiroki Nagai

52nd International Conference on Environmental Systems　2023/07/16
Operating Characteristics of Cryogenic Loop Heat Pipes at Different Filling Pressures

Yasuhito Okano, Shintaro Sato, Naofumi Ohnishi, Hiroki Nagai

The 34th International Symposium on Space Technology and Science　2023/06/06
Visualization and Void Fraction Measurement of Condensation Flow in Nitrogen-Charged Cryogenic Loop Heat Pipes

Atsuhiro Gomi, Kimihide Odagiri, Yuki Sakamoto, Shun Okazaki, Hiroki Nagai, Hiroyuki Ogawa

The 34th International Symposium on Space Technology and Science　2023/06/07
Propeller Scale Effect on Fixed Wing within Propeller Slipstream at Low Reynolds Number

Yoshikatsu Furusawa, Keiichi Kitamura, Tsubasa Ikami, Masaki Okawa, Hiroki Nagai

The 34th International Symposium on Space Technology and Science　2023/06/08
Uncertainty Quantification of Thermal Analysis using POD-PIML Thermal Surrogate Model

Hiroto Tanaka, Daichi Yamashita, Hiroki Nagai

The 34th International Symposium on Space Technology and Science　2023/06/07
Thermal Design of a Small Re-entry Capsule during Re-entry

Takeshi Yokouchi, Masaki Okawa, Hiroki Nagai, Toshinori Kuwahara, Nobuo Sugiura, Yuji Saito, Ryoutarou Murakami

The 34th International Symposium on Space Technology and Science　2023/06/07
抗重力条件下における2m級窒素ループヒートパイプの熱輸送特性

小田切公秀, 常新雨, 永井大樹, 小川博之

第60回日本伝熱シンポジウム　2023/05/26
炭素繊維の配向性がCFRP埋込自励振動ヒートパイプの熱輸送性能に与える影響

松原幸世, 安藤麻紀子, 永井大樹

第60回日本伝熱シンポジウム　2023/05/26
逆止弁付き自励振動ヒートパイプの動作特性における逆止弁流動抵抗の影響

安藤麻紀子, 永井大樹

第60回日本伝熱シンポジウム　2023/05/26
OpenFOAMによるウィック構造内部の熱および物質移動に関する数値解析

張展鵬, SHEN Biao, 渡邊健斗, 松原幸世, 常新雨, 永井大樹

第60回日本伝熱シンポジウム　2023/05/26
揚力型再突入カプセルの遷音速自励振動に関する一自由度運動数値解析

岡野泰人, 佐藤慎太郎, 大西直文, 永井大樹

日本航空宇宙学会第54期年会講演会　2023/04/13
Physics Informed Machine Learningを用いた宇宙機の熱サロゲートモデル

田中寛人, 永井大樹

日本航空宇宙学会第54期年会講演会　2023/04/14
cntTSPを用いた前進飛行するロータの非定常流れ場構造の可視化

伊神翼, 西村練, 永井大樹

日本航空宇宙学会第54期年会講演会　2023/04/13
火星における飛行探査の可能性

永井大樹, 大山聖

日本航空宇宙学会第54期年会講演会　2023/04/13
低高度からの自由落下試験による新型カプセルの空力安定性評価

永田麻王, 川野理人, 伊神翼, 永井大樹, 山田和彦

日本航空宇宙学会第54期年会講演会　2023/04/13
揚力型再突入カプセルの遷音速動的不安定性に関する一自由度運動数値解析

岡野泰人, 佐藤慎太郎, 大西直文, 永井大樹

日本航空宇宙学会北部支部2023年講演会ならびに第4回再使用型宇宙輸送系シンポジウム　2023/03/22

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JSASS-2023-H050
High-efficiency Thermal Control System for Electric Aircraft using Vapor-Liquid Two-phase Thermal Control Technology International-presentation

Hiroki Nagai, Xinyu Chang

The 11th Asian Joint Conference on Propulsion and Power　2023/03/16

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AJCPP2023-111
陽極酸化アルミ被膜型感圧塗料(AA-PSP)を用いたソニックブームの可視化計測

阿部淳之介, 小川俊広, 永井大樹

2022年度衝撃波シンポジウム　2023/03/09

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2A2-4
陽極酸化アルミ被膜型感圧塗料を用いた衝撃波通過時の物体にかかる非定常力計測

玉熊慎太郎, 小川俊広, 永井大樹

2022年度衝撃波シンポジウム　2023/03/09

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2A2-3
再突入カプセル模型周りの非定常流れ場に対する定量的可視化計測

片桐優太郎, 猪狩優斗, 高坂菜央, 山岸雅人, 太田匡則, 川野理人, 永井大樹

2022年度衝撃波シンポジウム　2023/03/09

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2A1-2
弾道飛行装置を用いた再突入カプセル模型周りの密度場計測

山岸雅人, 廣瀬裕介, 太田匡則, 細野陽太, 大谷清伸, 永井大樹

2022年度衝撃波シンポジウム　2023/03/09

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2A1-1
陽極酸化アルミ被膜型感圧塗料(AA-PSP)を用いた超音速で自由飛行する物体の表面圧力測定

滝川侑弥, 細野陽太, 小川俊広, 高橋幸一, 永井大樹

2022年度衝撃波シンポジウム　2023/03/09

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P13
Numerical Study on Suppression of Reentry Capsule Dynamic Instability in Transonic Flow International-presentation

Yasuhito Okano, Shintaro Sato, Naofumi Ohnishi, Hiroki Nagai

2023 AIAA SciTech Forum and Exposition　2023/01/24

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AIAA-2023-0811
Aspect Ratio Effect of Coaxial Rotor in Low Reynolds Number Condition International-presentation

Ren Nishimura, Masaki Okawa, Tsubasa Ikami, Hiroki Nagai

2023 AIAA SciTech Forum and Exposition　2023/01/26

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AIAA-2023-1974
Unsteady Interference between Propeller Slipstream and Flow Field around NACA0012 under Low Reynolds Number Condition International-presentation

Masaki Okawa, Ren Nishimura, Tsubasa Ikami, Hiroki Nagai

2023 AIAA SciTech Forum and Exposition　2023/01/26

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AIAA-2023-2293
平面衝撃波が様々な姿勢の円柱に及ぼす非定常流体力の研究

高橋俊, 玉熊慎太郎, 永井大樹

日本機械学会第35回計算力学会講演会　2022/11/16
Proposal of PSP Measurement Method Under Ambient Light

R. Tanaka, S. Katayama, T. Ikami, Y. Egami, H. Nagai, Y. Matsuda

19th International Conference on Flow Dynamics　2022/11/10

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OS13-3
Development of Pressure Distribution Measurement Technique for Free Flight Next-Generation Re-Entry Capsule (2)

H. Nagai, Y. Hosono, D. Kurihara, H. Sakaue

19th International Conference on Flow Dynamics　2022/11/10

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CRF-52
Development and Application of Ultra-Fast Pressure Sensitive Paint Technology

H. Nagai, S. Tamakuma, T. Ikami, S. Takahashi

19th International Conference on Flow Dynamics　2022/11/10

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CRF-51
Quantitative Density Measurement of Wake Region Behind Re-Entry Capsule: Improvement of the BOS Measurement System

M. Shirato, S. Nogi, S. Sato, M. Yamagishi, M. Ota, Y. Hosono, K. Ohtani, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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CRF-50
Study on Heat Transfer Characteristics of a 2 M Cryogenic Loop Heat Pipe with a Passive Capillary Starter Pump

K. Odagiri, X. Chang, H. Nagai, H. Ogawa

19th International Conference on Flow Dynamics　2022/11/10

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CRF-49
Postprocessing Method for Pressure-Sensitive Paint Data Based on Mathematical Optimization

K. Kubota, T. Inoue, T. Ikami, Y. Egami, H. Nagai, Y. Matsuda

19th International Conference on Flow Dynamics　2022/11/10

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CRF-48
Propeller-Slipstream/Main-Wing Aerodynamic Interaction for Mars Airplane, Part II

K. Kitamura, Y. Furusawa, T. Ikami, M. Okawa, K. Fujita, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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CRF-47
Numerical Simulation of 3-DOF Motion of a Return Capsule in Transonic Flow

S. Han, B. J. Lee, M. Ahn Furudate, K. Yomo, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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CRF-46
Propeller Wake Influence on Aerodynamic Characteristics of Mars Airplane in Preliminary Design

H. Nakamura, S. Horie, M. Kanazaki, K. Fujita, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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CRF-45
Analysis of High-Speed Plasma Flow on Space Transportation System

M. Takahashi, N. Tsunezawa, S. Suzuki, H. Sato, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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CRF-44
Computational and Experimental Study of Unsteady Flowfield Around Flexible-Membrane Wing at Low Reynolds Number Toward Mars Airplane

D. Sasaki, A. Nakaya, M. Okamoto, T. Akasaka, K. Fujita, S. Takahashi, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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CRF-43
Geometrically Nonlinear Beam Model for Slender Multibody Wings

K. Otsuka, Y. Wang, K. Cheng, S. Dong, K. Fujita, R. Palacios, H. Nagai, K. Makihara

19th International Conference on Flow Dynamics　2022/11/10

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CRF-42
Preliminary Study on Quadrotor Wake in Ground Effect Using Symmetry Walls

T. Hara, H. Otsuka, H. Tokutake, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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CRF-41
Simulation in Micro EHD Conduction Pump with Asymmetric Flush Electrode

T. Ueda, M. Nishikawara, H. Yanada, H. Yokoyama, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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CRF-3
Study of Heat and Mass Transport in Evaporation inside Porous Media

Z. Zhang, B. Shen, K. Watanabe, K. Matsubara, X. Chang, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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CRF-2
Clean Energy Power Generation Using Flow-Induced Self-Excited Vibration of an Elastic Body

K. Shige, N. Takeda, M. Okuno, T. Ikami, T. Kobayashi, O. Terashima, Y. Konishi, H. Nagai, T. Komatsuzaki

19th International Conference on Flow Dynamics　2022/11/10

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CRF-1
Unsteady Force Measurement on Cylinder Surface Using Anodized Aluminum Pressure-Sensitive Paint

S. Tamakuma, K. Yomo, T. Ogawa, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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OS21-57
Dynamic Stability Characteristics of Next Generation Re-entry Capsule at Transonic Speeds

R. Kawano, Y. Hamashima, M. Nagata, K. Takahashi, H. Nagai, K. Yamada

19th International Conference on Flow Dynamics　2022/11/10

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OS21-54
Free-fall Experiment of a New Re-entry Capsule Using Drone in Low-speed Region

M. Nagata, R. Kawano, K. Takahashi, K. Fujita, H. Nagai, K. Yamada

19th International Conference on Flow Dynamics　2022/11/10

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OS21-52
Pressure-sensitive Paint Technique on Free-flight Object Surface Using a Set of Pseudo-reference Images

Y. Hosono, K. Yomo, D. Kurihara, J. Gonzales, H. Sakaue, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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OS21-42
Unsteady Characteristics of Membrane Wing Applied Dielectric Elastomer Actuator

T. Kobayashi, K. Fujita, K. Otsuka, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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OS21-38
Effects of Oscillation of Flexible-membrane Wing on Flow Field at Low Reynolds Number

H. Kurahashi, K. Yamamoto, M. Okawa, T. Ikami, K. Takahashi, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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OS21-36
Time Response of Anodized Aluminum Pressure-Sensitive Paint for Supersonic Phenomena

S. Tamakuma, J. Abe, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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OS21-34
Numerical Study on Propeller Scale Effect on Flow Field around Blade

Y. Furusawa, K. Kitamura, T. Ikami, M. Okawa, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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OS21-31
Visualization of Coaxial Rotor at Low Reynolds Number Condition

R. Nishimura, M. Okawa, T. Ikami, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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OS21-29
Stall Delay in Propeller Slipstream at Low Reynolds Number

M. Okawa, R. Nishimura, T. Ikami, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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OS21-28
Visualization of Rotor Surface Flow in Hovering by cntTSP

T. Ikami, R. Nishimura, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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OS21-26
Experimental Study on Thermal Performance of CFRP-embedded Oscillating Heat Pipe

K. Matsubara, K. Sone, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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OS21-15
Numerical Analysis of Oscillating Heat Pipe with Dynamic Liquid Film Model

A. Kawaguchi, K. Sone, K. Matsubara, H. Nagai

19th International Conference on Flow Dynamics　2022/11/09

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OS21-13
Data-Driven Thermal Analysis for Spacecraft Systems -Evaluation of Temperature Estimation by Physics-Informed Neural Networks-

H. Tanaka, H. Nagai

19th International Conference on Flow Dynamics　2022/11/10

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OS21-12
Design Study of Loop Heat Pipe for kW-class Heat Transfer Applications

X. Chang, T. Tada, H. Nagai

19th International Conference on Flow Dynamics　2022/11/11
A Study of Surface Pressure Variation Induced by Planar Shock Wave Impinging on a Circular Cylinder from Various Angles

S. Takahashi, S. Tamakuma, T. Ikami, H. Nagai

19th International Conference on Flow Dynamics　2022/11/11
Flow Field and Aerodynamic Characteristics of Next- generation Re-entry Capsules of Different Shapes at Transonic Free Flight

Y. Takikawa, Y. Hosono, K. Takahashi, T. Ogawa, H. Nagai, K. Yamada

19th International Conference on Flow Dynamics　2022/11/11
Experimental Study on Operating Characteristics of Gravity-Assisted Cryogenic Loop Heat Pipe

Takeshi Yokouchi, Xinyu Chang, Kimihide Odagiri, Hiroyuki Ogawa, Hosei Nagano, Hiroki Nagai

19th International Conference on Flow Dynamics　2022/11/10

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OS21-14
数理最適化を用いた感圧塗料計測データの処理手法

窪田航陽, 井上智輝, 伊神翼, 江上泰広, 永井大樹, 松田佑

第50回可視化情報シンポジウム　2022/08/08
UNSTEADY PRESSURE DISTRIBUTION MEASUREMENT ON CYLINDER SURFACE USING ANODIZED ALUMINUM PRESSURE-SENSITIVE PAINT DURING SHOCK WAVE PASSAGE

S. Tamakuma, K. Yomo, T. Ogawa, H. Nagai

The 13th Pacific Symposium on Flow Visualization and Image Processing　2022/08/07
DEVELOPMENT OF PRESSURE DISTRIBUTION MEASUREMENT TECHNOLOGY ON FREE-FLIGHT OBJECT SURFACE AT TRANSONIC SPEED

Y. Hosono, K. Yomo, K. Takahashi, T. Ogawa, K. Ohtani, H. Nagai

The 13th Pacific Symposium on Flow Visualization and Image Processing　2022/08/07
NOISE SUPPRESSION METHOD FOR PSP DATA BASED ON REDUCED-ORDER MODELING

T. Inoue, Y. Matsuda, T. Ikami, T. Nonomura, Y. Egami, H. Nagai

The 13th Pacific Symposium on Flow Visualization and Image Processing　2022/08/07
FREQUENCY RESPONSE OF CARBON-NANOTUBE TEMPERATURE-SENSITIVE PAINT

T. Ikami, K. Takahashi, Y. Konishi, H. Nagai

The 13th Pacific Symposium on Flow Visualization and Image Processing　2022/08/07
Supercritical Startup Experiment of Cryogenic Loop Heat Pipe for Deep Space Mission International-presentation

Takeshi Yokouchi, Xinyu Chang, Hiroki Nagai, Kimihide Odagiri, Hiroyuki Ogawa, Hosei Nagano

51th International Conference on Environmental Systems　2022/07/10

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ICES-2022-76
Evaluation of temperature estimation accuracy using Physics-Informed Neural Network for small satellite model International-presentation

Hiroto Tanaka, Koji Fujita, Hiroki Nagai

51th International Conference on Environmental Systems　2022/07/10
Thermal Vacuum Testing of Advanced Thermal Control Devices for Flight Demonstration International-presentation

Satoshi Kajiyiama, Takuji Mizutani, Takuya Ishizaki, Kota Tomioka, Hosei Nagano, Hiroto Tanaka, Hiroki Nagai, Kan Matsumoto, Kenichiro Sawada, Yoshihiro Machida, Kazuaki Matsumoto

51th International Conference on Environmental Systems　2022/07/09

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ICES-2022-187
低レイノルズ数における柔軟膜翼の非定常流れ場解析

永井大樹, 山本健太郎, 伊神翼, 大川真生, 藤田昂志

第54回流体力学講演会／第40回航空宇宙数値シミュレーション技術シンポジウム　2022/06/29

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1B09
カーボンナノチューブ感温塗料の周波数応答

伊神翼, 高橋幸一, 小⻄康郁, 永井大樹

第54回流体力学講演会／第40回航空宇宙数値シミュレーション技術シンポジウム　2022/06/29

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1A11
誘電エラストマーアクチュエータ型柔軟膜翼における予ひずみと膜厚の空力特性への影響

小林達矢, 藤田昂志, 永井大樹

第54回流体力学講演会／第40回航空宇宙数値シミュレーション技術シンポジウム　2022/06/29

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1B08
低レイノルズ数において後縁剥離を伴う翼周り流れ場とプロペラ後流の非定常干渉

大川真生, 伊神翼, 藤田昂志, 永井大樹

第54回流体力学講演会／第40回航空宇宙数値シミュレーション技術シンポジウム　2022/06/29

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1B13
低レイノルズ数条件下における同軸反転ロータのアスペクト比の違いによる性能調査

西村練, 大川真生, 伊神翼, 藤田昂志, 永井大樹

第54回流体力学講演会／第40回航空宇宙数値シミュレーション技術シンポジウム　2022/06/29

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1B12
Unsteady Flow Field on Wing Surface in Propeller Slipstream at Low Reynolds Number

Tsubasa Ikami, Koji Fujita, Hiroki Nagai

2022 AIAA Aviation and Aeronautics Forum and Exposition　2022/06/27
動的液膜モデルを付加した自励振動ヒートパイプの数値解析

曽根航平, 松原幸世, 永井大樹

第 59 回日本伝熱シンポジウム　2022/05/19

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H323
マルチエバポレータ型極低温ループヒートパイプの熱輸送モデル構築と特性評価

小田切公秀, 常新雨, 永井大樹, 小川博之

第 59 回日本伝熱シンポジウム　2022/05/19

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H234
宇宙機の高精度温度制御に向けたループヒートパイプの蒸発器コアにおける沸騰の影響に関する数値解析

安達拓矢, 常新雨, 永井大樹

第 59 回日本伝熱シンポジウム　2022/05/19

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H233
宇宙用観測機器の冷却を目指した極低温ループヒートパイプに関する研究

横内岳史, 常新雨, 小田切公秀, 長野方星, 小川博之, 永井大樹

第59伝熱シンポジウム　2022/05/19

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H232
宇宙機のラジエータパネルへの適用を目指したCFRP埋込自励振動ヒートパイプに関する研究

松原幸世, 曽根航平, 永井大樹

第 59 回日本伝熱シンポジウム　2022/05/19

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H222
宇宙機熱制御への適用を目指した逆止弁付き自励振動型ヒートパイプの循環流化に関する一考察

安藤麻紀子, 曽根航平, 永井大樹

第 59 回日本伝熱シンポジウム　2022/05/19

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H221
Sensor Selection Algorithm for Post Processing of PSP Data using Digital Annealer International-presentation

Tomoki Inoue, Tsubasa Ikami, Hiroki Nagai, Yasuhiro Egami, Yasuo Naganuma, Koichi Kimura, Yu Matsuda

7TH THERMAL AND FLUIDS ENGINEERING CONFERENCE　2022/05/18

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40732
Methodology of Reliable Startup of Oscillation Heat Pipe International-presentation

Hiroki Nagai

7TH THERMAL AND FLUIDS ENGINEERING CONFERENCE　2022/05/18

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41241
次世代再突入カプセルの自由落下挙動計測の試み

永田麻生, 濱島優大, 藤田昂志, 永井大樹, 高橋幸一, 山田和彦

日本航空宇宙学会北部支部2022年講演会　2022/03/17

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JSASS-2022-H003
火星ヘリコプタ用同軸反転ロータの後流流れ場構造の解明

西村練, 大川真生, 伊神翼, 藤田昂生, 永井大樹

日本航空宇宙学会北部支部2022年講演会　2022/03/17

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JSASS-2022-H003
遷音速で自由飛行する物体表面の革新的圧力分布計測技術の研究

四方一真, 田中直樹, 高橋幸一, 小川俊広, 大谷清伸, 藤田昂志, 永井大樹, 山田和彦

日本機械学会東北支部第57回総会・講演会　2022/03/11
陽極酸化アルミ被膜型感圧塗料を用いた衝撃波通過時の円柱表面の非定常圧力分布計測

玉熊慎太郎, 四方一真, 小川俊広, 藤田昂志, 永井大樹

2021年度衝撃波シンポジウム　2022/03/10

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2A-1
低レイノルズ数におけるプロペラ後流中の翼面上非定常流れ場の調査

大川真生, 伊神翼, 藤田昂志, 永井大樹

東北学生会第52回学生員卒業研究発表講演会　2022/03/08

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132
Deployable Micro-Mars Airplane Stowed in 1U Cubesat International-presentation

Hiroto Tanaka, Tsubasa Ikami, Kohei Sone, Yudai Hamashima, Kohei Takeda, Kento Kaneko, Kazuma Yomo, Kose Matsubara, Tatsuya Kobayashi, Maki Okawa, Koji Fujita, Hiroki Nagai

33rd International Symposium on Space Technology and Science　2022/03/02

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2022-I-17
A New Way to Explore Mars with a Micro-size Airplane in the Sky -Mars Shot PLUS- International-presentation

Hiroki Nagai

33rd International Symposium on Space Technology and Science　2022/03/02

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2022-k-25
Development of Multibody Dynamics Formulation Based on Canonical Theory International-presentation International-coauthorship

Shuonan Dong, Keisuke Otsuka, Yinan Wang, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

33rd International Symposium on Space Technology and Science　2022/03/02

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2022-c-8
軽量・無電力型高機能熱制御デバイス（Advanced Thermal Control Device, ATCD）の軌道上実証状況 Invited

永井大樹, 田中寛人, 梶山聡史, 水谷琢志, 石崎拓也, 冨岡孝太, 長野方星, 松本貫, 下田優弥, 澤田健一郎, 町田洋弘, 松本一昭

革新的衛星技術実証ワークショップ2022　2022/02/17
植物の微小重力下における太陽光影響評価に向けた ISS 曝露部搭載型植物培養器(Plant-BioCube Unit)の開発に関する進捗状況 2021

日出間純, 愿山郁, 桒原聡文, 笠羽康正, 久米篤, 永井大樹, 橋本博文, 稲富裕光

第 36回宇宙環境利用シンポジウム　2022/01/18
Nonlinear Aeroelastic Analysis Coupling Unsteady Vortex Lattice Method and Strain-Based Beam Formulation International-presentation International-coauthorship

Keisuke Otsuka, Shuonan Dong, Yinan Wang, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

18th International Conference on Flow Dynamics　2021/10/27
Two-Phase Flow Simulation of Heat Pipe Using Sharp-Interface Level Set Method with Phase Change International-presentation

Yuki Kawamoto, Shun Takahashi, Shuusuke Kawamata, Shotaro Nara, Hiroki Nagai

18th International Conference on Flow Dynamics　2021/10/27
Quantitative Density Measurement of Wake Region behind reentry capsule International-presentation

M. Yamagishi, J. Narayama, S. Sato, M. Ota, Y. Hirose, K. Yomo, K. Fujita, K. Ohtani, H. Nagai

18th International Conference on Flow Dynamics　2021/10/27
Numerical Investigation: Influence of Propeller Wake on Mars Exploration Airplane’s Stability International-presentation

H. Nakamura, S. Horie, M. Kanazaki, K. Fujita, H. Nagai

18th International Conference on Flow Dynamics　2021/10/27
Numerical simulation of flowfields over Mars entry capsules III International-presentation International-coauthorship

Michiko Ahn Furudate, Minji Jo, Bok Jik Lee, Kazuma Yimo, Yudai Hamashima, Hiroki Nagai

18th International Conference on Flow Dynamics　2021/10/27
Numerical Study on Transonic Flow Characteristics over Return Capsules International-presentation International-coauthorship

Seoeum Han, Bok Jik Lee, Michiko Ahn Furudate, Kazuma Yomo, Hiroki Nagai

18th International Conference on Flow Dynamics　2021/10/27
Development of a thermal-vacuum chamber for study on cryogenic heat transfer device International-presentation

Kimihide Odagiri, Masaru Saijo, Kenichiro Sawada, Tomihiro Kinjo, Yuki Akizuki, Keisuke Shinozaki, Hiroyuki Ogawa, Hosei Nagano, Xinyu Chang, Hiroki Nagai

18th International Conference on Flow Dynamics　2021/10/27
Establishment of High-accuracy Analysis Method of Spacecraft Thermal System using Data Assimilation (3) International-presentation

Hiroki Nagai, Hiroto Tanaka, Takashi Misaka

18th International Conference on Flow Dynamics　2021/10/27
Development of pressure distribution measurement technique for free flight next generation re-entry capsule International-presentation International-coauthorship

H. Nagai, K. Yomo, K. Fujita, D. Kurihara, J. Gonzales, H. Sakaue

18th International Conference on Flow Dynamics　2021/10/27
Proposal of a Noise Reduction Method for Pressure-Sensitive Paint Data Using Mathematical Optimization International-presentation

Tomoki Inoue, Yu Matsuda, Tsubasa Ikami, Taku Nonomura, Yasuhiro Egami, Hiroki Nagai

18th International Conference on Flow Dynamics　2021/10/27
Thermal state estimation via artificial neural network for spacecraft systems International-presentation

Hiroto Tanaka, Koji Fujita, Hiroki Nagai

18th International Conference on Flow Dynamics　2021/10/27
Effect of Anisotropic Thermal Conductivity of CFRP on Heat Transport Performance of Oscillating Heat Pipe International-presentation

Kosei Matsubara, Koji Fujita, Hiroki Nagai

18th International Conference on Flow Dynamics　2021/10/27
Low-speed aerodynamic testing of next-generation re-entry capsule for deep space exploration International-presentation

Yudai Hamashima, Tsubasa Ikami, Koich Takahashi, Koji Fujita, Hiroki Nagai, Kazuhiko Yamada

18th International Conference on Flow Dynamics　2021/10/27
Aerodynamic Characteristics and Flow Field of Free-flight Re-entry Capsules International-presentation

Kazuma Yomo, Naoki Tanaka, Koichi Takahashi, Toshihiro Ogawa, Kiyonobu Ohtani, Koji Fujita, Hiroki Nagai, Kazuhiko Yamada

18th International Conference on Flow Dynamics　2021/10/27
Start-up Characteristics of Oscillating Heat Pipes with Hydrophobic Channel International-presentation

Kento Watanabe, Kohei Sone, Koji Fujita, Hiroki Nagai

18th International Conference on Flow Dynamics　2021/10/27
Effect of the Number of turns in Closed-End Oscillating Heat Pipe International-presentation

Kohei Sone, Kosei Matsubara, Kento Watanebe, Koji Fujita, Hiroki Nagai

18th International Conference on Flow Dynamics　2021/10/27
Understanding of Flow-Field of Pitching Airfoil at Low Reynolds Number International-presentation

Yuko Yoshizane, Tsubasa Ikami, Koji Fujita, Hiroki Nagai

18th International Conference on Flow Dynamics　2021/10/27
Consideration of Suppression of Self-excited Oscillation by Different Re-entry Capsule Shapes International-presentation

Masayuki Nomura, Koji Fujita, Hiroki Nagai

18th International Conference on Flow Dynamics　2021/10/27
Unsteady Flow Field around Flexible-membrane Wing at Low Reynolds Number International-presentation

Kentaro Yamamoto, Tsubasa Ikami, KoichiTakahashi, Koji Fujita, Hiroki Nagai

18th International Conference on Flow Dynamics　2021/10/27
Numerical Study on Mach Number Effects of Propeller on Propeller-Wing Interaction International-presentation

Yoshikatsu Furusawa, Keiich Kitamura, Hiroki Nagai

18th International Conference on Flow Dynamics　2021/10/27
Numerical Analysis of Two-Phase Mechanically Pumped Fluid Loop for Thermal Control of Electric Aircraft Motors International-presentation

Xinyu Chang, Koji Fujita, Hiroki Nagai

18th International Conference on Flow Dynamics　2021/10/27
Propeller Slipstream /Main Wing Aerodynamic Interaction for Mars Airplane International-presentation

Keiich Kitamura, Yoshikatsu Furusawa, Tsubasa Ikami, Koji Fujita, Hiroki Nagai

18th International Conference on Flow Dynamics　2021/10/27
DYNAMIC MODE DECOMPOSITION ANALYSIS OF KARMAN VORTEX STRUCTURE MEASURED BY UNSTEADY PSP - INVESTIGATION OF EFFECT OF SAMPLING FREQUENCY ON SPATIO-TEMPORAL FEATURES -

Tsubasa Ikami, Koji Fujita, Hiroki Nagai, Yu Matsuda, Yasuhiro Egami

The 19th International Symposium on Flow Visualization　2021/09/16
PSP denoising method based on POD and LASSO regression

Tomoki Inoue, Yu Matsuda, Tsubasa Ikami, Taku Nonomura, Yasuhiro Egami, Hiroki Nagai

The 19th International Symposium on Flow Visualization　2021/09/14
Comparison between closed-end oscillating heat pipe and closed-loop oscillating heat pipe by numerical calculation International-presentation

Kohei Sone, Koji Fujita, Hiroki Nagai

Joint 20th International Heat Pipe Conference and 14th International Heat Pipe Symposium　2021/09/07
人工ニューラルネットワークを用いた熱システム状態推定におけるセンサ配置評価

田中寛人, 藤田昂志, 永井大樹

日本機械学会2021年度年次大会　2021/09/06
扁平管往復曲げ構造を有する自励振動ヒートパイプの熱輸送性能に関する数値解析

松原幸世, 曽根航平, 永井大樹, 安田陽介, 鍋島史花

混相流シンポジウム 2021　2021/08/23
管断面形状の違いによる自励振動ヒートパイプの性能に関する数値解析

曽根航平, 松原幸世, 安田陽介, 鍋島史花, 永井大樹

混相流シンポジウム 2021　2021/08/23
中性子ラジオグラフィによる自励振動ヒートパイプ内部の作動液挙動の可視化

安田陽介, 鍋島史花, 堀内敬介, 永井大樹

混相流シンポジウム 2021　2021/08/23
Development of an Advanced Thermal Mathematical Model Construction Method for Spacecraft using Artificial Neural Network

Hiroto Tanaka, Koji Fujita, Hiroki Nagai

50th International Conference on Environmental Systems　2021/07/15
Development of Cryogenic loop heat pipe for deep space mission

Xinyu Chang, Takuya Adachi, Hiroki Nagai, Kimihide Odagiri, Hiroyuki Ogawa

50th International Conference on Environmental Systems　2021/07/14
Numerical simulation of heat transport characteristics of CFRP embedded Oscillating Heat Pipes for space application

Kosei Matsubara, Kohei Sone, Koji Fujita, Hiroki Nagai

50th International Conference on Environmental Systems　2021/07/14
Parametric Study for Vapor-Liquid Separation in Evaporator of Two-Phase Mechanical pump Fluid Loop System for Lunar and Planetary Exploration

Rin Asato, Takuya Adachi, Hiroki Nagai, Shun Okazaki, Atsushi Okamoto

50th International Conference on Environmental Systems　2021/07/14
On-orbit demonstration of Advanced Thermal Control Devices using JAXA Rapid Innovative payload demonstration SatellitE-2 (RAISE-2)

Hiroki Nagai, Hiroto Tanaka, Satoshi Kajiyama, Hosei Nagano, Kenichiro Sawada, Kan Matsumoto, Yuya Shimoda

50th International Conference on Environmental Systems　2021/07/14
Integrated Simulation of Aerodynamics, Propulsion, and Structure to Establish Design Study Techniques for Propeller-Driven Small Aircraft

2021/07/09
遷音速での自励振動を軽減する再突入カプセルの実験的評価

野村将之, 藤田昂志, 永井大樹

第53回流体力学講演会／第39回航空宇宙数値シミュレーション技術シンポジウム　2021/06/30
遷音速自由飛行する次世代再突入カプセルの流れ場と飛行特性

四方一真, 伊田中直樹, 高橋幸一, 小川俊宏, 大谷清伸, 藤田昂志, 永井大樹, 山田和彦

第53回流体力学講演会／第39回航空宇宙数値シミュレーション技術シンポジウム　2021/06/30
次世代再突入カプセルの低速飛行時の空力特性とその流れ場

濱島優大, 伊神翼, 高橋幸一, 藤田昂志, 永井大樹, 山田和彦

第53回流体力学講演会／第39回航空宇宙数値シミュレーション技術シンポジウム　2021/06/30
低レイノルズ数における同軸反転ロータの空力性能に対するアスペクト比とレイノルズ数の影響

山口敦士, 藤田昂志, 高橋幸一, 永井大樹

第53回流体力学講演会／第39回航空宇宙数値シミュレーション技術シンポジウム　2021/06/30
低レイノルズ数下でのプロペラ後流中における主翼表面上の非定常流れ場の解明

伊神翼, 林孝亮, 藤田昂志, 永井大樹

第53回流体力学講演会／第39回航空宇宙数値シミュレーション技術シンポジウム　2021/06/30
低レイノルズ数における柔軟膜翼の非定常流れ場のPIV解析

山本健太郎, 伊神翼, 高橋幸一, 藤田昂志, 永井大樹

第53回流体力学講演会／第39回航空宇宙数値シミュレーション技術シンポジウム　2021/06/30
液膜内部伝熱解析に向けたレベルセット法に基づく相変化解析手法の開発

川本裕樹, 奈良祥太朗, 高橋俊, 永井大樹

第 58 回日本伝熱シンポジウム　2021/05/26
数値計算による非ループ型自励振動ヒートパイプのターン数による影響の調査

曽根航平, 藤田昂志, 永井大樹

第 58 回日本伝熱シンポジウム　2021/05/26
自励振動ヒートパイプの流路断面形状による伝熱性能比較

安田陽介, 鍋島史花, 堀内敬介, 永井大樹

第 58 回日本伝熱シンポジウム　2021/05/26
CFRP 埋込型自励振動ヒートパイプの熱輸送性能に関する数値シミュレーション

松原幸世, 藤田昂志, 永井大樹

第 58 回日本伝熱シンポジウムプログラム　2021/05/26
宇宙機用極低温ループヒートパイプの設計試作とその評価

常新雨, 小田切公秀, 安達拓矢, 小川博之, 永井大樹

第 58 回日本伝熱シンポジウム　2021/05/26
火星の空を翔る超小型飛行機による新たな探査手段の提案 −マーズショット PLUS −

永井大樹

日本航空宇宙学会北部支部2021年講演会　2021/03/18
誘電エラストマアクチュエータを用いた膜翼による空力特性の向上に関する基礎研究

小林達矢, 藤田昂志, 永井大樹

日本航空宇宙学会北部支部2021年講演会　2021/03/19
展開式膜翼を用いた超小型火星飛行機の概念検討

李本茂, 藤田昂志, 永井大樹

日本航空宇宙学会北部支部2021年講演会　2021/03/18
再突入カプセル形状の違いが動特性に及ぼす影響の風洞試験による評価

野村将之, 藤田昂志, 永井大樹

日本航空宇宙学会北部支部2021年講演会　2021/03/18
Deep Neural Network を用いた熱数学モデルのコリレーション

田中寛人, 永井大樹, 藤田昂志

日本航空宇宙学会北部支部2021年講演会　2021/03/18
次世代再突入カプセルの弾道飛行装置を用いた自由飛行試験

四方一真, 田中直樹, 高橋幸一, 小川俊広, 大谷清伸, 藤田昂志, 永井大樹, 山田和彦

2020年度衝撃波シンポジウム　2021/03/03
火星の空を翔る超小型飛行機による新たな探査手段の提案 -マーズショットPLUS-

永井大樹

超小型探査機を用いた月以遠深宇宙探査に関する研究会　2021/02/08
Response Evaluation of cntTSP for Detection of Dynamic Boundary Layer Transition in Low-Speed Wind Tunnel

Tsubasa Ikami, Koji Fujita, Hiroki Nagai, Daisuke Yorita

AIAA SciTech 2021 Forum　2021/01/11
Experimental Investigation on Aerodynamic Performance of Coaxial Rotor at Low Reynolds Numbers

Atsushi Yamaguchi, Raoul Sunil Golani, Koji Fujita, Hiroki Nagai

AIAA SciTech 2021 Forum　2021/01/15
Permeable membrane wing characteristics at Reynolds number order of 10,000

Koji Fujita, Koichi Takahashi, Hiroki Nagai

AIAA SciTech 2021 Forum　2021/01/14
植物の微小重力下における太陽光影響評価に向けた ISS 曝露部搭載型植物培養器 (Plant-BioCube Unit)の開発に関する進捗状況

日出間純, 愿山(岡本)郁, 笠羽康正, 桒原聡文, 久米篤, 永井大樹, 橋本博文, 稲富裕光

第21回宇宙科学シンポジウム　2021/01/06
宇宙線反粒子探索GAPS実験計画の近況報告

福家英之, 小財正義, 小川博之, 岡崎峻, 西城大, 徳永翔, 山谷昌大, 吉田哲也, 中上裕輔, 和田拓也, 吉田篤正, 今村光拓, 清水雄輝, 山田昇, 小池貴久, 加藤千尋, 宗像一起, 永井大樹, 今西優香, 河内明子, 小林聖平, 本木誠人, 奈良祥太朗, 高橋俊, 竹村薫, 井上剛良, Hailey Charles, Perez Kerstin, Fabris Lorenzo, Craig William, Ong Rene, Boggs Steven, Doetinchem Philip von, Boezio Mirko

第21回宇宙科学シンポジウム　2021/01/06
極低温熱制御デバイスの開発

永井大樹, 常新雨, 安達拓矢, 小田切公秀, 西城大, 澤田健一郎, 金城富宏, 秋月祐樹, 篠崎慶亮, 小川博之, 上野藍, 長野方星

第21回宇宙科学シンポジウム　2021/01/06
火星希薄大気を模擬した低レイノルズ数領域におけるピッチ振動する翼の空力特性

吉實優子, 伊神翼, 藤田昂志, 永井大樹

令和2年度宇宙航行の力学シンポジウム　2020/12/14
深宇宙からのサンプルリターンに向けた次世代再突入カプセルの低速域における空力特性

濱島優大, 伊神翼, 高橋幸一, 藤田昂志, 永井大樹, 山田和彦

令和2年度宇宙航行の力学シンポジウム　2020/12/14
CFRP埋込型自励振動ヒートパイプの熱輸送特性に関する数値シミュレーション

松原幸世, 藤田昂志, 永井大樹

令和2年度宇宙航行の力学シンポジウム　2020/12/15
宇宙機の極低温ミッション用ループヒートパイプの設計検討

常新雨, 小田切公秀, 安達拓也, 小川博之, 永井大樹

令和2年度宇宙航行の力学シンポジウム　2020/12/15
月惑星探査のための二相メカニカルポンプループシステム蒸発器における気液分離試験結果

安里輪, 安達拓矢, 常新雨, 藤田昂志, 永井大樹, 岡崎峻, 岡本篤

令和2年度宇宙航行の力学シンポジウム　2020/12/15
ループヒートパイプの蒸発器コア内における相変化現象の数値解析

安達拓矢, 藤田昂志, 永井大樹

令和2年度宇宙航行の力学シンポジウム　2020/12/15
深宇宙からのサンプルリターンに向けた次世代再突入カプセルの弾道飛行装置を用いた自由飛行試験

四方一真, 田中直樹, 高橋幸一, 小川俊広, 大谷清伸, 藤田昂志, 永井大樹, 山田和彦

令和2年度宇宙航行の力学シンポジウム　2020/12/14
Deep Neural Networkを用いた宇宙機システムの熱コンダクタンス推定

田中寛人, 永井大樹, 藤田昂志, 小川博之

令和2年度宇宙航行の力学シンポジウム　2020/12/15
再突入カプセルの自励振動を軽減する形状の風洞試験における評価

野村将之, 藤田昂志, 永井大樹

令和2年度宇宙航行の力学シンポジウム　2020/12/14
マーズショットPLUS ー超小型火星飛行機による火星探査ー

永井大樹

令和2年度宇宙航行の力学シンポジウム　2020/12/14
第二回火星飛行機高高度飛行試験へ向けた空力モデルの構築

谷口翔太, 橘高洋人, 金崎雅博, 永井大樹, 大山聖, 藤田昂志, 安養寺正之, 岡本正人

令和2年度宇宙航行の力学シンポジウム　2020/12/15
非定常cntTSP計測における迎角振動翼での境界層遷移位置評価手法の比較

伊神翼, 藤田昂志, 永井大樹

第58回飛行機シンポジウム　2020/11/26
電動航空機モーターの熱制御を目指した 2相メカニカルポンプループの熱解析モデルの構築

常新雨, 藤田昂志, 永井大樹

第58回飛行機シンポジウム　2020/11/26
非定常PSP 計測でのデータ取得条件が動的モード分解に与える影響の調査

伊神翼, 藤田昂志, 永井大樹, 松田佑, 江上泰広

第16回学際領域における分子イメージングフォーラム　2020/11/19
構造化照明を用いた感圧塗料計測実験の提案

片山哲, 松田祐, 江上泰広, 伊神翼, 永井大樹

第16回学際領域における分子イメージングフォーラム　2020/11/19
ピッチスイープする翼を用いたcntTSPの時間応答性の調査

伊神翼, 藤田昂志, 永井大樹

第16回学際領域における分子イメージングフォーラム　2020/11/19
第 2 回火星飛行機高高度飛行試験 (MABE2) の準備状況 (その 2)

大山聖, 永井大樹, 藤田昂志, 安養寺正之, 岡本正人, 金崎雅博, 高野敦, 竹内伸介, 安部明雄, 佐々修一, 満武勝嗣, 得竹浩

2020年度大気球シンポジウム　2020/11/06
Numerical Investigation on Three-Dimensional Flow Structure over Fixed Wing within Propeller Slipstream

Yoshikatsu Furusawa, Keiichi Kitamura, Hiroki Nagai, Akira Oyama

Seventeenth International Conference on Flow Dynamics　2020/10/29
Flexible Wing Fluid-Structure Interaction Model Coupling Unsteady Vortex Lattice Method and Absolute Nodal Coordinate Formulation

Keisuke Otsuka, Shuonan Dong, Yinan Wang, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

Seventeenth International Conference on Flow Dynamics　2020/10/29
Numerical Study on Transonic Flow Characteristics over Return Capsules

Seoeum Han, Bok Jik Lee, Michiko Ahn Furudate, Nomura Masayuki, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/29
Development of PSP Measurement Technique Using Structured Illumination

Satoshi Katayama, Yu Matsuda, Yasuhiro Egami, Tsubasa Ikami, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/29
Numerical simulation of flowfields over Mars entry capsules II

Michiko Ahn Furudate, Dongoh Seo, Bok Jik Lee, Nomura Masayuki, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/29
Qualitative Density Measurement of Wake Region behind re-entry capsule: Improvements in Accuracy of 3D Reconstruction by Evaluating the View-Angle of Measurement System

Masato Yamagishi, Yusuke Yahagi, Masanori Ota, Yusuke Hirose, Shinsuke Udagawa, Tatsuro Inage, Shigeya Kubota, Koji Fujita, Kiyonobu Ohtani, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/29
Efficient Flight Simulation of MABE-2 Toward Global Trajectory Optimization

Masahiro Kanazaki, Hiroto Kittaka, Koji Fujita, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/29
Study of Coaxial Inversion Rotor Aimed at Realizing Mars Helicopter (3)

Hiroki Nagai, Koji Fujita, Atsushi Yamaguchi, Akira Oyama, Kouichi Yonezawa, Keiichi Kitamura, Yoshikatsu Furusawa, Makoto Sato, Masahiro Kanazaki

Seventeenth International Conference on Flow Dynamics　2020/10/29
Establishment of High-accuracy Analysis Method of Spacecraft Thermal System Using Data Assimilation (2)

Hiroki Nagai, Hiroto Tanaka, Takashi Misaka

Seventeenth International Conference on Flow Dynamics　2020/10/29
Surface Pressure Measurements using Two-Color PSP over a Free Flight Object in a Ballistic Range Facility -2

Daiki Kurihara, Joseph Gonzales, Hirotaka Sakaue, Naoki Tanaka, Kazuma Yomo, Koji Fujita, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/29
Preliminary Evaluation of Permeability Effect on Membrane Wing at Low Reynolds Number

Koji Fujita, Koichi Takahashi, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/28
Numerical Study of Compressibility of Airfoil Characteristics in Low Reynolds Number Flow

Yuko Yoshizane, Koji Fujita, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/28
System Analysis of a Two-Phase Mechanically Pumped Fluid Loop with a Heat Pump for Spacecraft

Rin Asato, Takuya Adachi, Xinyu Chang, Koji Fujita, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/28
Sensitivity Analysis of Observation Point for Data Assimilation : Application to Thermal Analysis of Pseudo Small Satellite

Hiroto Tanaka, Koji Fujita, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/28
An Attempt to Measure Pressure Distribution on a Free-Flight Object

Naoki Tanaka, Koji Fujita, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/28
Evaluation of Boundary Layer Transition Positions on Pitching Airfoil for Unsteady cntTSP Measurement

Tsubasa Ikami, Koji Fujita, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/28
Experimental Investigation on Rotor Performance of Mars Helicopter for Pit Crater Exploration

Atsushi Yamaguchi, Koji Fujita, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/28
Characteristics of Flexible Membrane Wing for Micro Mars Airplane

Benmao Lee, Koji Fujita, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/28
Investigation of the Effect of Propeller Thickness-wise Position on Aerodynamic Performance in Fixed Wing at Low Reynolds Number

Kosuke Hayashi, Koichi Takahashi, Koji Fujita, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/28
Effect of Wettability on Start-up Characteristic of OHP

Kento Watanabe, Takuya Adachi, Koji Fujita, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/28
Gravity Effect on Operating Characteristics of CEOHP by Numerical Simulation

Kohei Sone, Koji Fujita, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/28
Design study of cryogenic loop heat pipe for space application

Xinyu Chang, Takuya Adachi, Kimihide Odagiri, Hiroyuki Ogawa, Hiroki Nagai

Seventeenth International Conference on Flow Dynamics　2020/10/28
A Parametric Study for Avoiding Temperature Oscillation of a Loop Heat Pipe

Takuya Adachi, Koji Fujita, Hiroki Nagai, Shun Takahashi

Seventeenth International Conference on Flow Dynamics　2020/10/28
軽量・無電力型高機能熱制御デバイスの軌道上実証 (2)

永井大樹, 長野方星, 澤田健一郎, 松本貫

第64回宇宙科学技術連合講演会　2020/10/27
大気球試験機の空力―飛行シミュレーションに基づく大域的飛行・空力制御の最適化

橘高洋人, 金崎雅博, 藤田昂志, 永井大樹

第64回宇宙科学技術連合講演会　2020/10/27
進行率が異なる場合のプロペラ後流が固定翼に与える影響の変化に関する数値解析

古澤善克, 北村圭一, 永井大樹, 大山聖

第64回宇宙科学技術連合講演会　2020/10/27
MABE2における空力モデルの構築

谷口翔太, 橘高洋人, 金崎雅博, 永井大樹, 大山聖, 藤田昂志, 安養寺正之, 岡本正人

第64回宇宙科学技術連合講演会　2020/10/27
大気球を利用した火星飛行機の高高度飛行試験 MABE2

大山聖, 永井大樹

第64回宇宙科学技術連合講演会　2020/10/27
マーズショット PLUS −火星の空を翔る超小型飛行機による新たな探査手段の提案−

永井大樹

第64回宇宙科学技術連合講演会　2020/10/27
展開式膜翼を用いた超小型火星飛行機の概念設計

李本茂, 藤田昂志, 永井大樹

第64回宇宙科学技術連合講演会　2020/10/27
火星ヘリコプタ実現に向けた同軸反転ロータの空力性能に対する翼型の影響

山口敦士, 藤田昂志, 永井大樹

第64回宇宙科学技術連合講演会　2020/10/27
火星飛行機の高高度実証試験（MABE-2）における機体システムの熱解析

田中寛人, 藤田昂志, 大山聖, 永井大樹

第64回宇宙科学技術連合講演会　2020/10/27
光学式モーションキャプチャによる慣性センサの精度評価

藤田昂志, 大山聖, 久保大輔, 永井大樹

第64回宇宙科学技術連合講演会　2020/10/27
Development of Prediction Model for Heat Pipe Performance Using One Dimensional Discrete Bubble Model

Kaoru Takemura, Shotaro Nara, Shun Takahashi, Hiroki Nagai, Takuya Adachi

Seventeenth International Conference on Flow Dynamics　2020/10/29
通気性を有する膜翼のレイノルズ数10,000オーダーにおける空力特性

藤田昂志, 高橋幸一, 永井大樹

流体力学講演会／航空宇宙数値シミュレーション技術シンポジウム2020オンライン　2020/09/30
ルテニウム型高速応答感圧塗料を用いた低速流れ場の微小圧力変動計測

江上泰広, 長谷川敦也, 松田佑, 伊神翼, 永井大樹

流体力学講演会／航空宇宙数値シミュレーション技術シンポジウム2020オンライン　2020/09/28
非定常PSP計測における固有直行分解と動的モード分解のノイズ除去効果

森重聡一郎, 山﨑遊野, 松田佑, 伊神翼, 永井大樹, 江上泰広

第48回可視化情報シンポジウム　2020/09/24
非定常PSP計測における動的モード分解のデータ取得条件の調査

伊神翼, 藤田昂志, 永井大樹, 松田佑, 山崎遊野, 江上泰広

第48回可視化情報シンポジウム　2020/09/24
自励振動ヒートパイプのターン数と内部流動との関係

渡邊健斗, 藤田昂志, 永井大樹

混相流シンポジウム 2020　2020/08/23
ループ型および非ループ型自励振動ヒートパイプの内部特性調査

曽根航平, 藤田昂志, 永井大樹

混相流シンポジウム 2020　2020/08/23
ループヒートパイプにおける温度振動の発生条件解明に向けた数値解析

安達拓矢, 藤田昂志, 永井大樹, 高橋俊

混相流シンポジウム 2020　2020/08/23
Design for Large Isothermal Evaporator Mounted on Two-Phase Mechanically Pumped Fluid Loop

Hiroki Nagai, Takumi Hirata, Koji Fujita, Shun Okazaki, Atsushi Okamoto

50th International Conference on Environmental Systems　2020/07/13
Data Assimilation Applied Thermal Analysis of Mars Airplane for High-Altitude Flight Test (MABE2)

Hiroto Tanaka, Takashi Misaka, Hiroki Nagai

50th International Conference on Environmental Systems　2020/07/13
ターン数の違いによる自励振動ヒートパイプの性能評価

永井大樹, 長澤滉生, 渡邊健斗, 曽根航平

第 57 回日本伝熱シンポジウム　2020/06/03
数値計算による非ループ型と閉ループ型自励振動ヒートパイプの比較

曽根航平, 藤田昂志, 永井大樹

第 57 回日本伝熱シンポジウム　2020/06/03
ヒートパイプの流動予測に向けた気泡モデルの開発

高橋俊, 奈良祥太朗, 長島弘明, 竹村薫, 安達拓矢, 永井大樹, 岡崎峻, 福家英之

第 57 回日本伝熱シンポジウム　2020/06/03
ループヒートパイプにおける凝縮を伴う二相流の非定常解析

安達拓矢, 藤田昂志, 永井大樹, 高橋俊

第 57 回日本伝熱シンポジウム　2020/06/03
弾道飛行装置実験により自由飛行するカプセルの遷音速域における後流の時空間構造の特徴抽出

桐谷英樹, 永井大樹, 藤田昂志, 大谷清伸

2019年度衝撃波シンポジウム　2020/03/05
自由飛行するカプセルの遷音速領域における後流の時空間構造の特徴抽出解析

永井大樹

令和元年度航空宇宙空力シンポジウム　2020/01/25
Detection Methods in a Pitch-sweep Test by means of TSP using Lifetime and Intensity Measurements

Daisuke Yorita, Jonathan Lemarechal, Christian Klein, Koji Fujita, Hiroki Nagai

AIAA SciTech 2020 Forum　2020/01/06
Measurement of Boundary Layer Transition on Oscillating Airfoil using cntTSP in Low Speed Wind Tunnel

Tsubasa Ikami, Koji Fujita, Hiroki Nagai, Daisuke Yorita

AIAA SciTech 2020 Forum　2020/01/06
Surface Pressure Measurements over a Free Flight Object in a Ballistic Range Facility using Two-Color Pressure-Sensitive Paint

Daiki Kurihara, Steve Claucherty, Joe Gonzales, Hirotaka Sakaue, Hideki Kiritani, Koji Fujita, Hiroki Nagai

AIAA SciTech 2020 Forum　2020/01/06
Experimental and RANS analysis of Full Mars Airplane Configurations

Shota Taniguchi, Akira Oyama, Masato Okamoto, Masayuki Anyoji, Koji Fujita, Hiroki Nagai

AIAA SciTech 2020 Forum　2020/01/10
Parametric Study on Mars Helicopter for Pit Crater Exploration

Koji Fujita, Hilal Karaca, Hiroki Nagai

AIAA SciTech 2020 Forum　2020/01/10
Wing Model Using ANCF and UVLM: Multibody Dynamic Simulation and Wind Tunnel Experiment

Keisuke Otsuka, Yinan Wang, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

AIAA SciTech 2020 Forum　2020/01/09
Surface Pressure Measurements over a Free Flight Object in a Ballistic Range Facility using Two- Color Pressure-Sensitive Paint

Daiki Kurihara, Steven Claucherty, Joseph Gonzales, Hirotaka Sakaue, Hideki Kiritani, Koji Fujita, Hiroki Nagai

AIAA Scitech 2020 Forum　2020/01/06
Experimental and RANS analysis of full Mars airplane configurations

Shota Taniguchi, Akira Oyama, M Okamoto, Masato Okamoto, Masayuki Anyoji, Koji Fujita, Hiroki Nagai

AIAA Scitech 2020 Forum　2020/01/10
Parametric Study of Mars Helicopter for Pit Crater Exploration

Koji Fujita, Hilal Karaca, Hiroki Nagai

AIAA Scitech 2020 Forum　2020/01/09
Deployable Wing Model Using ANCF and UVLM: Multibody Dynamic Simulation and Wind Tunnel Experiment

Keisuke Otsuka, Yinan Wang, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

AIAA Scitech 2020 Forum　2020/01/09
Blade Element Theory Coupled with CFD Applied to Optimal Design of Rotor for Mars Exploration Helicopter

Kazufumi Uwatoko, Masahiro Kanazaki, Hiroki Nagai, Koji Fujita, Akira Oyama

AIAA Scitech 2020 Forum　2020/01/08
Transition Detection Methods in a Pitch-sweep Test by means of TSP using Lifetime and Intensity Measurements

Daisuke Yorita, Jonathan Lemarechal, Christian Klein, Koji Fujita, Tsubasa Ikami, Hiroki Nagai

AIAA Scitech 2020 Forum　2020/01/06
Experimental Studies on Effects of Mach Number and Specific Heat Ratio on Low-Reynolds-Number Airfoils Invited

Masayuki Anyoji, Daiju Numata, Hiroki Nagai, Keisuke Asai

AIAA Scitech 2020 Forum　2020/01/06
Transonic Flow Field Analysis of a Free Flight Capsule using Ballistic Range

Hideki Kiritani, Naoki Tanaka, Kiyonobu Ohtani, Koji Fujita, Hiroki Nagai

AIAA Scitech 2020 Forum　2020/01/10
Measurement of Boundary Layer Transition on Oscillating Airfoil using cntTSP in Low-Speed Wind Tunnel

Tsubasa Ikami, Koji Fujita, Hiroki Nagai, Daisuke Yorita

AIAA Scitech 2020 Forum　2020/01/06
MACO計画における飛行機を用いたRSL観測の可能性

藤田昂志, 永井大樹, 大山聖, 藤田和央

第20回宇宙科学シンポジウム　2020/01/08
将来ミッションに向けた高性能熱制御デバイスの研究

柴野靖子, 澤田健一郎, 西城大, 金城富宏, 小田切公秀, 小川博之, 長野方星, 永井大樹

第20回宇宙科学シンポジウム　2020/01/08
宇宙飛行体周りの流れ場の可視化 ―高速・高温流れの可視化計測― Invited

永井大樹

東海大学総合科学技術研究所 2019年度シンポジウム　2019/12/20
Influence of Vapor-Liquid Distribution on Startup Characteristics in a Loop Heat Pipe

Adachi, Koji Fujita, Hiroki Nagai

The 2nd Pacific Rim Thermal Engineering Conference　2019/12/14
Numerical Simulation of Internal Flow in Large Isothermal Evaporator of Two-Phase Mechanically Pumped Fluid Loop

Takumi Hirata, Takuya Adachi, Koji Fujita, Hiroki Nagai

The 2nd Pacific Rim Thermal Engineering Conference　2019/12/15
Study on Influence of Hydrophobic Surface on Startup Characteristics of Oscillating Heat Pipe

Hiroki Nagasawa, Takuya Adachi, Koji Fujita, Hiroki Nagai

The 2nd Pacific Rim Thermal Engineering Conference　2019/12/14
cntTSPを用いたピッチ振動翼上の非定常流れ場構造の調査

伊神翼, 依田大輔, Christian Klein, 藤田昂志, 永井大樹

第15回学際領域における分子イメージングフォーラム　2019/12/12
カプセル肩部周りの形状がピッチング振動へ及ぼす影響の風洞試験による評価

野村将之, 藤田昂志, 永井大樹

令和元年度宇宙航行の力学シンポジウム　2019/12/10
データ同化手法を用いた宇宙機熱状態推定手法の提案

田中寛人, 永井大樹, 三坂孝志

令和元年度宇宙航行の力学シンポジウム　2019/12/09
遷音速域において自由飛行するはやぶさカプセルの後流解析

桐谷英樹, 田中直樹, 藤田昂志, 小川俊広, 大谷清伸, 永井大樹

令和元年度宇宙航行の力学シンポジウム　2019/12/10
CubeSatへの搭載を想定した超小型火星飛行機の空力性能評価

間宮一誠, 藤田昂志, 永井大樹

令和元年度宇宙航行の力学シンポジウム　2019/12/09
宇宙で確実に始動し;持続的に作動する自励振動ヒートパイプに対する一考察

永井大樹

令和元年度宇宙航行の力学シンポジウム　2019/12/09
深宇宙探査などの極限環境下における熱制御システムとしての二相メカニカルポンプループシステムの提案

永井大樹

令和元年度宇宙航行の力学シンポジウム　2019/12/09
宇宙機の熱流体システムに関する研究 Invited

永井大樹

令和元年度宇宙航行の力学シンポジウム　2019/12/10
ループヒートパイプ起動時の輸送管内における流れの数値解析

安達拓矢, 藤田昂志, 永井大樹, 高橋俊

令和元年度宇宙航行の力学シンポジウム　2019/12/09
Aeroelastic Deformation Measurement of Mars Airplane for High-Altitude Flight Experiment Using Stereo Photogrammetry Technique

Shuichi Hiramatsu, Masayuki Anyoji, Koji Fujita, Hiroki Nagai, Akira Oyama, Hiroyuki Kato

The 11th International Meeting on Advances in Thermofluids　2019/11/07
Visualization study of multi-evaporators loop heat pipe under different heating conditions

Xinyu Chang, Hiroki Nagai, Noriyuki Watanabe, Hosei Nagano, Hiroyuki Ogawa

16th International Conference on Flow Dynamics　2019/11/08
Study on Effect of Vapor Flow Path Shape in Large Isothermal Evaporator of Two-Phase Mechanically Pumped Fluid Loop

Takumi Hirata, Takuya Adachi, Koji Fujita, Hiroki Nagai

16th International Conference on Flow Dynamics　2019/11/07
Study on Start-up Characteristics of the Hydrophobized OHP

Hiroki Nagasawa, Takuya Adachi, Koji Fujita, Hiroki Nagai

16th International Conference on Flow Dynamics　2019/11/07
Surface Pressure Measurements using Two-Color PSP over a Free Flight Object in a Ballistic Range Facility

Daiki Kurihara, Steven Claucherty, Joseph Gonzales, Hirotaka Sakaue, Hideki Kiritani, Koji Fujita, Hiroki Nagai

16th International Conference on Flow Dynamics　2019/11/07
Numerical Simulation of Flowfields Over Mars Entry Capsules

Michiko Ahn Furudate, Bok Jik Lee, Nomura Masayuki, Hiroki Nagai

16th International Conference on Flow Dynamics　2019/11/07
Investigation of a Time Response of cntTSP Sensor for a Dynamic Visualization of the Laminar-to-turbulent Boundary Layer Transition

Daisuke Yorita, Jonathan Lemarechal, Christian Klein, Koji Fujita, Tsubasa Ikami, Hiroki Nagai

16th International Conference on Flow Dynamics　2019/11/07
Establishment of High-accuracy Analysis Method of Spacecraft Thermal System using Data Assimilation

Hiroki Nagai, Hiroto Tanaka, Takashi Misaka

16th International Conference on Flow Dynamics　2019/11/07
Study of Coaxial Inversion Rotor Aimed at Realizing Mars Helicopter

Hiroki Nagai, Koji Fujita, Akira Oyama, Kouichi Yonezawa

16th International Conference on Flow Dynamics　2019/11/07
Triple-phase Contact Line Dynamics of Sticky and Slippery Surfaces

Raza Gulfam, Peng Zhang, Hiroki Nagai

16th International Conference on Flow Dynamics　2019/11/07
Application of Two-phase Thermo-fluid Simulation for Accurate Design of Oscillating Heat Pipe

Kaoru Takemura, Yuki Kawamoto, Shun Takahashi, Hiroaki Nagashima, Takuya Adachi, Hiroki Nagai

16th International Conference on Flow Dynamics　2019/11/07
Numerical Simulation of Dynamic Derivatives for Mars Airplane Balloon Experiment-2 (MABE-2)

Masahiro Kanazaki, Hiroto Kittaka, Akira Oyama, Koji Fujita, Hiroki Nagai

16th International Conference on Flow Dynamics　2019/11/07
Validation of Fast‐Pressure‐Sensitive Paint for Measuring Small Pressure Fluctuation

Yasuhiro Egami, Yuya Yamazaki, Yu Matsuda, Tsubasa Ikami, Hiroki Nagai

16th International Conference on Flow Dynamics　2019/11/07
Comparison of 2D and 3D Simulation Models for Deployable Wing

Keisuke Otsuka, Takahiro Suzaki, Yinan Wang, Koji Fujita, Hiroki Nagai, Kanjuro Makihara

16th International Conference on Flow Dynamics　2019/11/07
Thermal Analysis of Spacecraft using Data Assimilation

Hiroto Tanaka, Hiroki Nagai, Takashi Misaka

16th International Conference on Flow Dynamics　2019/11/07
Aerodynamic Design of Micro-size Mars Airplane

Issei Mamiya, Koji Fujita, Hiroki Nagai

16th International Conference on Flow Dynamics　2019/11/06
PIV Measurement of Oscillating Airfoil at Low Reynolds Number

Tsubasa Ikami, Koji Fujita, Hiroki Nagai

16th International Conference on Flow Dynamics　2019/11/06
Free-Flight Test of Different Re-Entry Capsule Shapes at Transonic Speed

Hideki Kiritani, Kiyonobu Ohtani, Hiroki Nagai

16th International Conference on Flow Dynamics　2019/11/06
第2回火星飛行機高高度飛行試験(MABE2)の準備状況

大山聖, 永井大樹, 藤田昂志, 安養寺正之, 岡本正人, 金崎雅博, 安部明雄, 佐々修一, 得竹浩, 高野敦, 満武勝嗣

2019年度大気球シンポジウム　2019/11
火星飛行機の高高度飛行試験計画MABE2の概要

大山聖, 永井大樹, 藤田昂志, 安養寺正之, 岡本正人, 金崎雅博, 安部明雄, 佐々修一, 得竹浩, 高野敦, 満武勝嗣

第63回宇宙科学技術連合講演会　2019/11
軽量・無電力型高機能熱制御デバイスの軌道上実証

永井大樹, 長野方星, 澤田健一郎, 松本貫, 野田香菜子, 秋月祐樹, 石崎拓也, 冨岡孝太, 水谷琢志, 小嶋涼太

第63回宇宙科学技術連合講演会　2019/11
RSL観測用火星飛行機の初期概念検討

藤田昂志, 永井大樹, 大山聖, 藤田和央

第63回宇宙科学技術連合講演会　2019/11
低速流れでの動的な境界層遷移計測におけるcntTSPの時間応答性の調査

伊神翼, 藤田昂志, 永井大樹, 依田大輔, Christian Klein

第57回飛行機シンポジウム　2019/11
Classification of Internal Flow Pattern of Oscillating Heat Pipe by Pressure Variation

Hiroki Nagai, Nao Inoue

1st International Symposium on Oscillating/Pulsating Heat Pipes (ISOPHP 2019)　2019/09/27
Numerical Simulation of Oscillating/Pulsating Heat Pipe to understand Internal Flow Invited

Hiroki Nagai

International Symposium on Oscillating/Pulsating Heat Pipes (ISOPHP 2019)　2019/09/27
Reliable Startup of Oscillating Heat Pipe for Space Application

Hiroki Nagai, Nao Inoue, Hiroki Nagasawa, Makiko Andoh, Rui Matsutomo, Atsushi Okamoto, Hiroyuki Sugita

1st International Symposium on Oscillating/Pulsating Heat Pipes (ISOPHP 2019)　2019/09/27
Experimental study on Start-up characteristics of Oscillating heat pipe with check valves

Makiko Ando, Atsushi Okamoto, Kousuke Tanaka, Rui Matsumoto, Nao Inoue, Hiroki Nagasawa, Hiroki Nagai

1st International Symposium on Oscillating/Pulsating Heat Pipes (ISOPHP 2019)　2019/09/26
Design of Micro-size Mars airplane deploying from CubeSat

2019/09/26
Surface Pressure Measurement of Free-Flight Sphere Using Motion-Capturing PSP Method

Naoki Tanaka, Hiroki Nagai, Hideki Kiritani, Daiki Kurihara, Joseph Gonzales, Hirotaka Sakaue

7th Japanese-German Joint Seminar -Molecular Imaging Technology for Interdisciplinary Research-　2019/09/17
Evaluation of cntTSP for Boundary Layer Transition Detection in Low Speed Flow

Tsubasa Ikami, Koji Fujita, Hiroki Nagai, Daisuke Yorita, Christian Klein

7th Japanese-German Joint Seminar -Molecular Imaging Technology for Interdisciplinary Research-　2019/09/17
Thermal Analysis of Spacecraft using Data Assimilation

Hiroto Tanaka, Hiroki Nagai, Takashi Misaka

Thermal & Fluid Analysis Workshop 2019　2019/08/29
Numerical Simulation of Transient Behavior of Vapor-Liquid Distribution in a Loop Heat Pipe

Takuya Adachi, Koji Fujita, Hiroki Nagai

Thermal & Fluid Analysis Workshop 2019　2019/08/27
気液二相流体メカニカルポンプループに搭載した大面積等温蒸発器における非等温現象の解明

平田拓巳, 安達拓矢, 藤田昂志, 永井大樹

混相流シンポジウム2019　2019/08/06
ループヒートパイプの起動特性に対する気液分布の影響

安達拓矢, 藤田昂志, 永井大樹

混相流シンポジウム2019　2019/08/06
Non-linear Effects of Pressure Disturbances on Sharp Cone Measured in High Enthalpy Shock Tunnel

Tatsuya Tonai, Katsuhiro Ito, Hideyuki Tanno, Hiroki Nagai

The 32nd International Symposia on Shock Waves　2019/07/18
An Experimental Attempt to Improve Start-up Characteristics of Oscillating Heat Pipe with Check Valves

Makiko Ando, Atsushi Okamoto, Kousuke Tanaka, Rui Matsumoto, Nao Inoue, Hiroki Nagasawa, Hiroki Nagai

49th International Conference on Environmental Systems　2019/07/07
カーボンナノチューブ感温塗料を利用した低速流れにおけるNACA0012翼の動的境界層遷移計測

伊神翼, 藤田昂志, 永井大樹, 依田大輔, Christian Klein

第51回流体力学講演会/第37回航空宇宙数値シミュレーション技術シンポジウム　2019/07/01
Quantitative Density Measurement of Unsteady Flow Field around A Sphere in The Ballistic Range

Masanori Ota, Yusuke Hirose, Kazuki Ishikawa, Yoshiyuki Ishimoto, Takumi Nagashima, Shinsuke Udagawa, Tatsuro Inage, Kazuki Fujita, Hideki Kiritani, Koji Fujita, Kiyonobu Ohtani, Hiroki Nagai

The 32nd International Symposia on Shock Waves　2019/07
Numerical Study for Reliable Start-up of Oscillating Heat Pipe with Surface Roughness

Hiroki Nagai, Nao Inoue, Hiroki Nagasawa, Makiko Ando, Rui Matsumoto, Atsushi Okamoto, Hiroyuki Sugita

32nd International Symposium on Space Technology and Science　2019/06/20
Research on Improving Performance of Coaxial Rotor of Mars Helicopter for Vertical Hole Exploration on Mars

Koji Fujita, Kensuke Kanou, Koichi Takahashi, Hiroki Nagai

32nd International Symposium on Space Technology and Science　2019/06/20
A Feasibility Analysis of Collaborative Mission Using Mars Airplane and Mars Balloon - Mars aerial-Exploration for Terrestrial and Tropospheric Environment Observation -

Hiroto Tanaka, Issei Mamiya, Hideki Kiritani, Hiroki Nagasawa, Takumi Hirata, Tatsuya Tonai, Hiroki Nagai, Koji Fujita

32nd International Symposium on Space Technology and Science　2019/06/20
表面特性に着目した自励振動ヒートパイプの始動特性改善

永井大樹, 井上菜生, 長澤滉生

第56回伝熱シンポジウム　2019/05/30
Experimental Investigation of Propeller Slipstream Effect on Membrane-Skin Wing at Low Reynolds Number

Koji Fujita, Kechacoop Kanbodin, Koichi Takahashi, Hiroki Nagai

16th International Conference on Flow Dynamics　2019/11/07
低速風洞での流れ場計測におけるcntTSPの応答性評価

伊神翼, 藤田昂志, 永井大樹, 依田大輔, Christian Klein

第47回可視化情報シンポジウム　2019/07/26
Aerodynamic characteristics of mars airplane airfoils with control surface in propeller slipstream

Kakeru Kurane, Kenta Uechi, Koichi Takahashi, Koji Fujita, Hiroki Nagai

AIAA Aerospace Sciences Meeting, 2018　2018/01/01

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© 2018, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. Aerodynamic characteristics of airfoils in a propeller slipstream were investigated at low Reynolds number. The effects of a propeller slipstream on control surface effectiveness were clarified by aerodynamic force measurement and the Particle Image Velocimetry (PIV) measurement. The tests were conducted using the small low-turbulence wind tunnel in the Institute of Fluid Science, Tohoku University, at the chord Reynolds number of 3.0×10 4 . The airfoils tested were the Ishii and T1-2 airfoils, the two main candidates for the Japanese Mars airplane. Two configurations were used in the testing, one configuration with a propeller set in front of the wing and one configuration without a propeller to be used as a baseline. For the case without the propeller, the Ishii airfoil control surface effectiveness increased according to the deflection angle. However, the effectiveness of the T1-2 airfoil did not increase at certain angles of attack. When the propeller was set, the effectiveness increased according to the deflection angle for both airfoils. These results indicate that a propeller would have a positive effect on controllability of a Mars airplane.
Aerodynamic Challenge for Realization of Mars Airplane

永井大樹, 大山聖, 安養寺正之, 岡本正人, 藤田昂志, 米本浩一

年会講演会講演集　2017/04/13
Overview of Mars Airplane Balloon Experiment-1 (MABE-1)

大山聖, 永井大樹, 得竹浩, 藤田昂志, 安養寺正之, 豊田裕之, 宮澤優, 米本浩一, 岡本正人, 野々村拓, 元田敏和, 竹内伸介, 鎌田幸男, 大槻真嗣, 浅井圭介, 藤井孝藏

年会講演会講演集　2017/04/13
Attitude Estimation on Mars Airplane Balloon Experiment-1 (MABE-1)

得竹浩, 藤田昂志, 大山聖, 永井大樹

年会講演会講演集　2017/04/13
Evolutionary Computation Approach to Control Parameter Optimization of Mars Airplane Balloon Experiment-1 (MABE-1)

藤田昂志, 永井大樹, 得竹浩, 大山聖

年会講演会講演集　2017/04/13
Aerodynamic Characteristics on Mars Airplane Balloon Experiment-1 (MABE-1)

安養寺正之, 岡本正人, 藤田昂志, 永井大樹, 大山聖

年会講演会講演集　2017/04/13
Thermal Analysis of Mars Airplane on Mars Airplane Balloon Experiment-1 (MABE-1)

永井大樹, 小田泰之, 大丸拓郎, 大山聖, 藤田昂志

年会講演会講演集　2017/04/13
Operating Characteristics of Loop Heat Pipe With Two Evaporators and Two Condensers under atmospheric condition

X. Chang, H. Nagano, S. Okazaki, H. Ogawa, H. Nagai

Proceedings of Asian Conference on Thermal Science 2017　2017/03
Global Heat Flux Measurement Using Temperature-Sensitive Paint in High-Enthalpy Shock Tunnel HIEST

T. Nagayama, H. Nagai, H. Tanno, T. Komuro

Proceedings of AIAA SciTech2017　2017/01
Dynamic stability drop tests with capsule shaped model

TANNO Hideyuki, KOMURO Tomoyuki, YAMADA Tetsuya, NAGAI Shinji, NAGAI Hiroki

The Proceedings of Mechanical Engineering Congress, Japan　2017

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A free-flight drop test is planned to evaluate aerodynamic stability of reentry capsules under subsonic condition. The final goal of the work is to obtain benchmarks of stability characteristics to compare with wind tunnel test results or CFD calculations. The model is a scaled models of a Japanese small reentry capsule, which diameter were 250mm. Nine onboard accelerometer modules are instrumented in the model to determine six-components aerodynamic characteristics. In the pre-drop test, acceleration histories are successfully measured with the onboard instruments, which demonstrates the feasibility of the present measurement scheme.
プロペラ設置位置による火星飛行機の空力性能向上について

平成28年度宇宙航行の力学シンポジウム　2016/12
火星飛行機の熱設計における不確定パラメータ推定への適用検討

平成28年度宇宙航行の力学シンポジウム　2016/12
数値解析を用いた自励振動ヒートパイプの逆止弁流動抵抗感度解析

平成28年度宇宙航行の力学シンポジウム　2016/12
大面積等温蒸発部を搭載した気液二相流体メカニカルポンプループの設計検討

平成28年度宇宙航行の力学シンポジウム　2016/12
非定常内部流動モデルによるループヒートパイプのスタートアップ現象の解明

平成28年度宇宙航行の力学シンポジウム　2016/12
Evaluation of the Thermal Analysis for Mars Airplane Balloon Experiment-1 International-presentation

4th International Forum on Heat Transfer　2016/11
Operating Characteristics of a Loop Heat Pipe with Two Evaporators and Two Condensers, Experiment Result and Mathematical Model under Thermal Vacuum Condition International-presentation

4th International Forum on Heat Transfer　2016/11
高温衝撃風洞HIESTにおける空力加熱率計測の定量的評価

第12回「学際領域における分子イメージングフォーラム」　2016/11
高高度飛行試験における火星飛行機の空力データ取得

平成28年度大気球シンポジウム　2016/11
高高度飛行試験における火星飛行機の空力データ取得

平成28年度宇宙航行の力学シンポジウム　2016/11
南極周回気球による宇宙線反粒子探索実験GAPSの現状報告

平成28年度大気球シンポジウム　2016/11
Effect of Propeller Positions and Rotation Directions on Wing at Low Reynolds Number International-presentation

13th International Conference on Flow Dynamics　2016/10
Effect of Propeller Positions and Rotation Directions on Wing at Low Reynolds Number International-presentation

The 2016 Asia-Pacific International Symposium on Aerospace Technology　2016/10
Evaluation of Effect of a Secondary Wick on Thermal Performance of a Loop Heat Pipe Using Simple Mathematical Model International-presentation

13th International Conference on Flow Dynamics　2016/10
Evaluation of Heat Flux Measurement Using Temperature-Sensitive Paint in High Enthalpy Shock Tunnel International-presentation

13th International Conference on Flow Dynamics　2016/10
Temperature Prediction of Mars Airplane Balloon Experiment-1 International-presentation

13th International Conference on Flow Dynamics　2016/10
火星飛行機の高高度飛行試験結果の速報

第54回飛行機シンポジウム　2016/10
Consideration on Startup Behavior in On-orbit Experiment of Oscillating Heat Pipe with Check Valves

大丸拓郎, 永井大樹, 安藤麻紀子, 田中洸輔, 岡本篤, 杉田寛之

宇宙科学技術連合講演会講演集　2016/09/06
セカンダリウィックがLoop Heat Pipe の熱輸送性能に与える影響の簡易数学モデルによる評価

安達拓矢, 大丸拓郎, 永井大樹

第60回宇宙科学技術連合講演会　2016/09/06
高高度飛行試験ミッションにおける火星探査飛行機の温度予測

小田泰之, 大丸拓郎, 永井大樹

第60回宇宙科学技術連合講演会　2016/09/06
将来深宇宙探査用二相流体メカニカルポンプループのシステム検討

坂元健一, 大丸拓郎, 永井大樹, Sunada Eric, Bhandari Pradeep, Furst Benjamin, Cappucci Stefano

第60回宇宙科学技術連合講演会　2016/09/06
Development of Japanese Mars Airplane International-presentation

67th International Astronautical Congress　2016/09
Effect of Yaw-tilted Hinge Axis on Deployment Robustness of Mars Airplane International-presentation

30th Congress of the International Council of the Aeronautical Sciences　2016/09
高温衝撃風洞HIESTにおける感温塗料技術を用いた空力加熱計測技術の現状

一般社団法人日本機械学会 2016年度年次大会　2016/09
System trade-off analysis of two-phase mechanically pumped fluid loop for thermal control of future deep space missions International-presentation

Thermal & Fluids Analysis Workshop TFAWS 2016　2016/08
圧力振動による自励振動ヒートパイプの内部流動様式の分類

日本混相流シンポジウム2016　2016/08
数値解析による平板型ヒートパイプ軌道上実験の検証

日本混相流シンポジウム2016　2016/08
A Two-Phase Mechanically Pumped Fluid Loop for Thermal Control of Deep Space Science Missions International-presentation

46th International Conference on Environmental Systems　2016/07
Comparison between Numerical Simulation and On-orbit Experiment of Oscillating Heat Pipes International-presentation

46th International Conference on Environmental Systems　2016/07
火星飛行機に最適化された主翼の空力特性に関する実験的評価

第48回流力講演会　2016/07
低レイノルズ数におけるプロペラ後流の影響を受ける石井翼の空力性能

第48回流力講演会　2016/07
A study on circulation flow of Oscillating Heat Pipe with check valves by visualization International-presentation

Joint 18th International Heat Pipe Conference and 12th International Heat Pipe Symposium　2016/06
高温衝撃風洞HIESTにおける感温塗料技術の適用とその評価

第44回可視化情報シンポジウム　2016/06
Research and Development Trend on Supersonic and Hypersonic Aerodynamic Decelerator in the world

永井大樹

年会講演会講演集　2016/04/14
国外における超音&極超音柔軟構空力減装置の研究開発の動向について

一般社団法人日本航空宇宙学会第47期年会講演会　2016/04
バリスティックレンジを用いたカプセル形状模型空力安定性評価

日本航空宇宙学会北部支部2016年講演会ならびに第17回再使用型宇宙推進系シンポジウム　2016/03
Development of Japanese mars airplane

Hiroki Nagai, Akira Oyama

Proceedings of the International Astronautical Congress, IAC　2016/01

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Copyright © 2016 by the International Astronautical Federation (IAF). All rights reserved. Mars is the next milestone in our exploration of the solar system. The presence of an atmosphere on Mars signifies that an airplane could travel in its atmosphere using the aerodynamic forces of flight. The airplane allows for a platform that can cover a larger area of exploration than is currently available. A reconnaissance airplane offers the possibility to obtain high-resolution data on a regional scale of several hundreds to thousands of kilometers, which cannot be achieved with rovers or satellites. There is an extremely high demand for the exploration of Mars using an airplane that can fly in its atmosphere. One of the big problems for a Mars Airplane is the very low atmospheric density on Mars. So, it is difficult to obtain the required lift, as the wing area required to generate enough lift is inversely proportional to the density. So in order to reduce the required lift, thorough weight reduction is needed. Even so, a Mars Airplane needs a large wing area, which leads to another problem. To transport to Mars, a Mars Airplane must be small and compact. As a way to solve this conflicting problem, the Mars Airplane needs some deployment mechanisms. Various hurdles, including those described above, must be overcome in order to realize the flight exploration of Mars and all of them require innovative technological solutions. Hence, the Mars Airplane Working Group was established in 2010 with the aim of conducting flight technology validations for the MELOS1 mission using a compact airplane in JAXA/ISAS. The working group aims to realize Mars exploration using an airplane for the first time ever. At present, the mission being considered for the Mars exploration plane is "flying over a range of about 100 km to capture ground surface images and observing high-resolution images of residual magnetic fields." Cameras and magnetic field observation equipment are mounted as payloads on the airplane, which is expected to fly over a range of 100 km at a speed of 60 m/s. In the conceptual design, the weight of the airplane is about 4.0 kg, the span length is about 2.5 m, and the total length is about 2.0 m. This paper provides a summary of the Mars airplane development being considered by the working group in Japan and discusses the technical issues addressed in order to realize a Mars airplane.
Effect of yaw-tilted hinge axis on deployment robustness of mars airplane

Koji Fujita, Hiroki Nagai, Akira Oyama

30th Congress of the International Council of the Aeronautical Sciences, ICAS 2016　2016/01

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This paper investigates the robustness of the aerial deployment behavior of the foldable-wing airplane for Mars exploration especially focused on the effect of the hinge axis tilting in a yaw direction. This study deals with four dispersive parameters for the robustness evaluation: drop velocity, surrounding gust velocity, initial pitch angle, and height. The robustness of several tilted and non-tilted hinge axis designs are calculated and then compared. The result clearly shows that the tilted hinge axis design can deploy with lower torque than the torque of the non-tilted hinge axis design. The increase of sideslip angle due to the hinge axis tilting suppressed an aerodynamic force on the deploying wing.
GAPS用大型自励振動ヒートパイプの開発

平成27年度宇宙科学シンポジウム　2016/01
Robust Aerial Deployment of Mars Airplane with Tilted Folding-Axis International-presentation

Koji Fujita, Hiroki Nagai, Akira Oyama

AIAA SciTech2016　2016/01/01

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© 2016, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. A folding wing is an effective deployment mechanism for the airplane that is used for Mars exploration. A spring loaded hinge is considered as a deployment actuator for Mars airplane in Japan. A hinge torque is one of the primitive design variables to control the aerial deployment behavior. The required hinge torque for deployment is directly concerned with the deployment mechanism mass. Since the Mars airplane requires thorough mass reduction, it is necessary to reduce the required hinge torque while keeping high robustness for the aerial deployment. This paper investigates the robustness of the aerial deployment behavior especially focused on the effect of the hinge axis tilting. The hinge axis of the non- tilted hinge axis design is defined to be parallel to the X-axis of the center body coordinates. The conditions to judge whether the deployment succeeded or failed are defined for the state of the airplane. The margins of the airplane state for the conditions are set to the evaluation functions of the safety. The robustness of the safety is evaluated using the sigma level where the sigma level is a function of the average and standard deviation of the evaluation functions. For the robustness evaluation, this study deals with four dispersive parameters: drop velocity, surrounding gust velocity, initial pitch angle, and height. The robustness of several tilted and non-tilted hinge axis designs are calculated and then compared. The result clearly shows that the tilted hinge axis design can deploy with lower torque than the torque of the non-tilted hinge axis design. The motions of the individual cases are then studied to reveal the effect of the hinge axis tilting. It is clarified that the tilted hinge axis design is able to set the angle of attack of the outer wing positive under the wide range of conditions. Therefore, the aerodynamic force assists the deployment. In the appropriate condition, the wings deploy without torque of the deployment actuator.
Visualization of Hypersonic Boundary Layer Transition on Elliptic Cone in High Enthalpy Shock Tunnel with Temperature-Sensitive Paint International-presentation

Takehiro Nagayama, Hiroki Nagai, Hideyuki Tanno, Tomoyuki Komuro

AIAA SciTech2016　2016/01/01

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© 2016, American Institute of Aeronautics and Astronautics Inc, AIAA. All Rights Reserved. A flow visualization with TSP (Temperature-sensitive paint) was given on the hypersonic boundary layer transition on an elliptic cone in the High Enthalpy Shock Tunnel JAXA-HIEST. The present study firstly investigated the issue of white basecoat thickness to the luminescent intensity and temperature sensitivity of TSP, which was particularly produced for short duration measurements. It was discovered that the thickness of basecoat does not touch on the characteristic of TSP. Moreover, thickness of 15 μm was found to raise the maximum luminescent intensity of TSP. With the basecoat and the TSP, surface temperature successfully visualized the hypersonic boundary layer transition on a side of the cone at stagnation enthalpy H 0 = 3.0 MJ/kg. Accuracy of the present measurement was discussed through the comparison with thermocouple measurements involving surface temperature augmentation due to boundary layer transition.
高温衝撃風洞HIESTにおける極超音速飛行体の境界層遷移可視化

平成 27年度航空宇宙空力シンポジウム　2016/01
将来宇宙機に適用する熱制御技術の開発

平成27年度宇宙科学シンポジウム　2016/01
南極周回気球による宇宙線反粒子探索計画GAPS

平成27年度宇宙科学シンポジウム　2016/01
南極周回気球による宇宙線反粒子探索計画GAPSの近況報告

日本物理学会第71回年次大会（2016年）　2016/01
Effects of Check Valves on Thermal and Flow Characteristics of Oscillating Heat Pipes

Takurou Daimaru, Shuhei Yoshida, Hiroki Nagai

Proceedings of the 12th International Conference on Flow Dynamics　2015/11

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Paper No.OS16-11
Flow Visualization of Oscillating Heat Pipe by X-ray Imaging Method

Shuhei Yoshida, Takurou Daimaru, Masahiro Kawaji, Hiroki Nagai

Proceedings of the 12th International Conference on Flow Dynamics　2015/11

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Paper No.OS16-9
Application of Temperature-Sensitive Paint to High-Enthalpy Shock Tunnel for Visualization of Boundary Layer Transition

Takehito Nagayama, Hiroki Nagai, Hideyuki Tanno, Tomoyuki Komuro

Proceedings of the 12th International Conference on Flow Dynamics　2015/11

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Paper No.OS16-10
Development of the Makita-Type Active Turbulence Grid for 03-m Wind Tunnel

Satoru Hatori, Hiroki Nagai, Daiju Numata, Keisuke Asai

Proceedings of the 12th International Conference on Flow Dynamics　2015/11

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Paper No.OS16-58
Evaluation of Aerodynamic Characteristics of an Optimized Airfoil for Mars Airplane

Kentarou Yamahara, Daisuke Oshiyama, Hiroki Nagai, Masahiro Kanazaki, Daiju Numata, Keisuke Asai

Proceedings of the 12th International Conference on Flow Dynamics　2015/11

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Paper No.OS16-67
Effect of Hinge Axis Tilting on Aerial Deployment of Mars Airplane

藤田昂志, 永井大樹, 大山聖

宇宙科学技術連合講演会講演集　2015/10/07
Thermal Design of DESTINY Using Advanced Thermal Control Technology

岡崎峻, 長野方星, 永井大樹

宇宙科学技術連合講演会講演集　2015/10/07
Effects of Check Valves on Operating Characteristics of Oscillating Heat Pipes

大丸拓郎, 吉田周平, 永井大樹

宇宙科学技術連合講演会講演集　2015/10/07
S1910301 Visualization of Boundary Layer Transition on HIFiRE Model in High-Enthalpy Shock Tunnel Using Temperature-Sensitive Paint

NAGAYAMA Takehiro, NAGAI Hiroki, TANNO Hideyuki, KOMURO Tomoyuki

Mechanical Engineering Congress, Japan　2015/09/13

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A visualization experiment of hypersonic boundary layer transition by Temperature-Sensitive Paint (TSP) was performed. The test facility was High-Enthalpy Shock Tunnel (HIEST) at Japan Aerospace Exploration Agency (JAXA) Kakuda Space Center. An elliptic cone model with a 2:1 aspect ratio, which is a full-scale model of HIFiRE-5, was used as the test model. This study visualized the hypersonic boundary layer transition on the side of the test model. TSP was excited by a Blue-LED and the luminescence from TSP was detected by a high-speed camera. Temperature distribution on the side of the test model was obtained by TSP. Moreover, boundary layer transition along the centerline of the model and in approximately halfway between the centerline and leading edge were visualized. The trend of temperature rise along the centerline is same in TSP and thermocouples, which is inserted on the centerline of the test model.
Visualization of Loop Heat Pipe with Multiple Evaporators under Microgravity

Hosei Nagano, Yuta Matsuda, Shun Okazaki, Hiroki Nagai, Hiroyuki Ogawa

Proceedings of the 45th International Conference on Environmental Systems　2015/07

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Paper No.ICES-2015-329
Parametric Study of Oscillating Heat Pipes by using Mathematical Model for Practical Use in Spacecraft

Takurou Daimaru, Shuhei Yoshida, Hiroki Nagai, Atsushi Okamoto, Makiko Ando, Hiroyuki Sugita

Proceedings of the 30th International Symposium on Space Technology and Science　2015/06

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Paper No.2015-i-04
Experimental Study in Effects of Secondary Wick Configuration on Thermal Performance of a Loop Heat Pipe

Masahiko Taketani, Takuya Adachi, Hiroki Nagai

Proceedings of the 30th International Symposium on Space Technology and Science　2015/06

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Paper No.2015-i-07
Conceptual Design Study of Oscillating Heat Pipe System for GAPS

Shun Okazaki, Hideyuki Fuke, Takayoshi Inoue, Akiko Kawachi, Daisuke Matsumoto, Yoshiro Miyazaki, Hiroki Nagai, Taku Nonomura, Hiroyuki Ogawa, Naoki Yamada

Proceedings of the 30th International Symposium on Space Technology and Science　2015/06

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Paper No.2015-i-08
Development of an Oscillating Heat Pipe Cooling System for GAPS

Hideyuki Fuke, Takayoshi Inoue, Akiko Kawachi, Daisuke Matsumoto, Yoshiro Miyazaki, Hiroki Nagai, Taku Nonomura, Hiroyuki Ogawa, Naoki Yamada

Proceedings of the 30th International Symposium on Space Technology and Science　2015/06

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Paper No.2015-i-10
A Parametric Study of Mars Airplane Concept for Science Mission on Mars

Koji Fujita, Hiroki Nagai, Akira Oyama

Proceedings of the 30th International Symposium on Space Technology and Science　2015/06

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Paper No.2015-k-45
Development of Mars Exploration Aerial Vehicle in Japan

Hiroki Nagai, Akira Oyama, Mars Airplane WG

Proceedings of the 30th International Symposium on Space Technology and Science　2015/06

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Paper No.2015-k-46
Aerodynamic Challenge to Realize Mars Airplane

Hiroki Nagai, Masayuki Anyoji, Taku Nonomura, Akira Oyama, Masato Okamoto, Gaku Sasaki, Takaaki Matsumoto, Kouichi Yonemoto, Kasahiro Kanazaki, Shigeru Sunada, Koichi Yonezawa, Masaru Koike, Koji Fujita, Keisuke Asai, Kozo Fujii

Proceedings of the 30th International Symposium on Space Technology and Science　2015/06

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Paper No.2015-k-47
Aerodynamic Characteristics of Airfoils with Different Aspect Ratio behind Propeller Slipstream in Low Reynolds Number Condition

Hiroki Nagai, Kotaro Watanabe, Koji Fujita

Proceedings of the 30th International Symposium on Space Technology and Science　2015/06

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Paper No.2015-k-51
Aerodynamic Evaluation of a Capsule Shaped Projectile during Free Flight Testing with Ballistic Range

Akiho Ishida, Hiroki Nagai, Hideyuki Tanno, Tomoyuki Komoro

AIAA SciTech 2015　2015/01

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Paper No.2015-0244
Conceptual Design of a Mars Airplane for a Technological Demonstrator of a Mars Lander

藤田昂志, 永井大樹, 大山聖

宇宙科学技術連合講演会講演集　2014/11/12
Aerodynamic Challenges to Realize Mars Airplane

永井大樹, 安養寺正之, 野々村拓

宇宙科学技術連合講演会講演集　2014/11/12
The Effects of Secondary Wicks Configuration on the Performance of Loop Heat Pipe

竹谷政彦, 永井大樹

宇宙科学技術連合講演会講演集　2014/11/12
A Consideration of Startup Behavior of Oscillating Heat Pipes

大丸拓郎, 吉田周平, 永井大樹

宇宙科学技術連合講演会講演集　2014/11/12
DESTINY : Understanding of Martian dust transport mechanisms

小郷原一智, 大山聖, 永井大樹

宇宙科学技術連合講演会講演集　2014/11/12
F224 Mathematical Modeling of Oscillating Heat Pipes with Check Valves

Daimaru Takurou, Yoshida Shuhei, Nagai Hiroki, Okamoto Atsushi, Ando Makiko, Sugita Hiroyuki

Procee[d]ings of Thermal Engineering Conference　2014/11/08

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A mathematical model of Oscillating Heat Pipes (OHPs) with check valves has been constructed. The mathematical model was a one-dimensional slug flow model. Movement of liquid slugs was governed by pressure differences among vapor plugs and by pressure drops in the tubes. Check valves were reproduced by change of liquid slug's momentum. As a result, check valves caused the circulation flow in OHP.
Visualization of Laminar to Turbulent Transition on Re-entry Capsule using TSP in High Enthalpy Shock Tunnel

Takehiro Nagayama, Takehito Horagiri, Hiroki Nagai, Hideyuki Tanno, Tomoyuki Komuro

Proceedings of the 11th International Conference on Flow Dynamics　2014/10

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Paper No.OS10-48
Numerical Investigation of the Effects of Initial Liquid-Vapor Distribution in Oscillating Heat Pipes

Takurou Daimaru, Shuhei Yoshida, Hiroki Nagai, Atsushi Okamoto, Makiko Ando, Hiroyuki Sugita

Proceedings of the 11th International Conference on Flow Dynamics　2014/10

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Paper No.GS1-16
Study of Motion Modeling for a Capsule Shaped Projectile in Free flight Testing at Transonic

Akiho Ishida, Hiroki Nagai, Hideyuki Tanno, Tomoyuki Komoro

Proceedings of the 11th International Conference on Flow Dynamics　2014/10

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Paper No.GS1-22
Improvement of Startup Characteristics of a Loop Heat Pipe using Secondary Wicks

Masahiko Taketani, Hiroki Nagai

Proceedings of the 11th International Conference on Flow Dynamics　2014/10

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Paper No.GS1-15
Effect of blade wake by means of interference with propeller slipstream on low Reynolds number condition

Satoru Hattori, Kotaro Watanabe, Hiroki Nagai

Proceedings of the 11th International Conference on Flow Dynamics　2014/10

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Paper No.OS10-17
Aerodynamic performance of optimized airfoil for Mars Airplane using Multi-objective generic algorithm

Kentaro Yamahara, Hiroki Nagai, Takaya Sato, Masahiro Kanazaki

Proceedings of the 11th International Conference on Flow Dynamics　2014/10

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Paper No.OS10-19
S1910203 The Aerodynamic Characteristics Evaluation of Capsule Model in Free Flight Testing

Ishida Akiho, Nagai Hiroki, Tanno Hideyuki, Komuro Tomoyuki

Mechanical Engineering Congress, Japan　2014/09/07

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The HTV Return Vehicle (HRV) is a re-entry capsule with a blunt body that is being considered by Japan Aerospace Exploration Agency (JAXA) as a new space vehicle. The aerodynamic characteristics must be clarified for the HRV design and trajectory because of the capsule's dynamic instability at transonic. A single degree-of-freedom free-rotation test method in a wind tunnel was employed in a previous study. In this study, free flight tests of a re-entry lifting capsule were conducted in the JAXA HEK-G Ballistic Range. The motion in free flight was measured by four acceleration sensors for the pitching and yawing directions. The angular acceleration data from the tests under the same conditions are compared and discussed.
Numerical Study of Wind-Tunnel Acoustic Resonance induced by Two-Dimensional Airfoil Flow at Low Reynolds Number

Tomoaki Ikeda, Takashi Atobe, Yasuhiro Konishi, Hiroki Nagai, Keisuke Asai

Proceedings of the 29th Congress of the International Council of the Aeronautical Science　2014/09

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Paper No.2014-0195
Mathematical Modeling and Experimental Validation of Oscillating Heat Pipes

Takurou Daimaru, Shuhei Yoshida, Hiroki Nagai, Atsushi Okamoto, Makiko Ando, Hiroyuki Sugita

Proceedings of 44rd International Conference on Environmental Systems　2014/07

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ICES-2014-121
Operation Characteristics of Loop Heat Pipes with PTEF and SUS wicks

Shun Okazaki, Hosei Nagano, Hiroki Nagai, Hiroyuki Ogawa

Proceedings of 44rd International Conference on Environmental Systems　2014/07

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ICES-2014-249
Effects of Secondary Wicks on the Thermal Performance of a Loop Heat Pipe

Masahiko Taketani, Hiroki Nagai

Proceedings of 44rd International Conference on Environmental Systems　2014/07

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ICES-2014-115
Visualization of a Re-entry Vehicle in Hypersonic Flow using Temperature-Sensitive Paint

Hiroki Nagai, Takehito Horagiri, Hideyuki Tannno, Tomoyuki Komuro

Proceedings of the 16th International Symposium on Flow Visualization　2014/06

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Paper No.ISFV16-1275
Numerical analysis for an aerial deployment motion of a folded-wing airplane

Koji Fujita, Koji Fujita, Toshikazu Motoda, Toshikazu Motoda, Hiroki Nagai, Hiroki Nagai

AIAA Atmospheric Flight Mechanics Conference　2014/02/28

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An airplane has been planned to be used for Mars exploration. The wing folding technology for such an airplane has been paid attention to because it offers a large wing area to get enough lift force and compactness for transfer to Mars. In addition, aerial deployment allows for using the initial altitude to its advantage. However, aerial deployment motion is complex and has a possibility of failure. This paper presents the result of a numerical analysis for the aerial deployment motion of a folded-wing airplane. The requirements for successful aerial wing deployment were defined. The sensitivity analysis results are evaluated using the requirements. Successful input range, and lower and upper constraints are revealed. The most sensitive requirement is the hinge reaction moment. Successful combinations among a spring, a damper, and aerodynamic force for the safe aerial deployment were quantitatively obtained.
Numerical Analysis for an Aerial Deployment Motion of a Folded-Wing Airplane

Fujita, K, Motoda, T, Nagai, H

Proceedings of AIAA SciTech2014　2014/01

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AIAA 2013-0383
Development of Temperature-Sensitive Paint with High Performance and Responsivity for Aerodynamic Heating Measurement

Horagiri, T, Nagai, H

Proceedings of AIAA SciTech2014　2014/01

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AIAA 2013-1408
Propeller Slipstream Interference with Wing Aerodynamic Characteristics of Mars Airplane at Low Reynolds Number

Makino, F, Nagai, H

Proceedings of AIAA SciTech2014　2014/01

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AIAA 2013-0744
Numerical study of wind-tunnel acoustic resonance induced by two-dimensional airfoil flow at low reynolds number

Tomoaki Ikeda, Takashi Atobe, Yasufumi Konishi, Hiroki Nagai, Keisuke Asai

29th Congress of the International Council of the Aeronautical Sciences, ICAS 2014　2014/01

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In the aeroacoustic measurements of a windtunnel test, the acoustic resonance should be avoided, associated with the walled test section. The present numerical study of an NACA0012 airfoil focuses on how the wall resonance affects unsteady flow motions via a feedback process, by comparing with the airfoil placed in a free stream. Tonal frequencies observed in the present simulations agree well with our previous wind-tunnel experiments, represented approximately by the discrete resonant modes derived through a simple geometrical relation. More importantly, however, the present results indicate that rather strong wall resonance may alter the hydrodynamic flow measurements as well. The acoustic feedback process stimulates the transitional boundary layer on the suction side, which would increase lift force in the acoustically resonant channel by suppressing trailing-edge separation. At a higher angle of attack, the increment of lift force becomes more significant due to the noticeable size reduction of a separation bubble, understood via the comparison of three-dimensional instantaneous vortical structures.
Flow-Coupled Multibody Dynamics Simulation for an Aerial Deployment of a Folded Wing

Fujita, K, Motoda, T, Nagai, H

Proceedings of 10th International Conference on Fluid Dynamics　2013/11/25
Aerodynamic Influence of a Propeller Wake on NACA0012 Airfoil at Low Reynolds Number

Makino. F, Nagai, H

Proceedings of 10th International Conference on Fluid Dynamics　2013/11/25
Effect of Secondary Wick on Startup Process of Loop Heat Pipe

Taketani. M, Nagai, H

Proceedings of 10th International Conference on Fluid Dynamics　2013/11/25
Development of Phosphor-TSP for High-Temperature Distribution Measurement

Ishida, A, Nagai, H

Proceedings of 10th International Conference on Fluid Dynamics　2013/11/25
Development of High-Performance TSP by Mixing Fine Particle

Horagiri, T, Nagai, H

Proceedings of 10th International Conference on Fluid Dynamics　2013/11/25
0901 Numerical Study of Shock Interaction over Compression Corner with 30 deg. in Hypersonic Flow : Unsteady Characteristics of Flow Field.

KURAMOTO Takeshi, MUTOH Daiki, TSUBOI Nobuyuki, NAGAI Hiroki, ASAI Keisuke

Fluids engineering conference ...　2013/11/09

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In hypersonic flow, the shock interactions cause high surface heat flux. Furthermore, the unsteady vortices are generated over a compression corner. Present study investigates the relation between the distribution of the surface heat flux and the unsteady vortices. The flow field over the compression corner with 30 deg. is calculated by the three-dimensional numerical simulations. The heat flux distributions on the model surface show some unsteady longitudinal streaks, because the longitudinal vortices merge and separate cyclically.
Mission Scenario of Mars Exploration by Airplane

Nagai, H, Oyama, A

Proceedings of The 2013 Asia-Pacific International Symposium on Aerospace Technology　2013/11

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08-01-3p
Aerial-Wing-Deployment Simulation of the Folded-Wing Airplane with Individual Aerodynamic Characteristics

Fujita, K, Motoda, T, Nagai, H

Proceedings of The 2013 Asia-Pacific International Symposium on Aerospace Technology　2013/11
Preliminary Design and Thermal Analysis of Miniature Mars Airplane Thermal Control System

大丸拓郎, 永井大樹

宇宙科学技術連合講演会講演集　2013/10/09
Effects of Secondary Wick on Thermal Characteristics of Loop Heat Pipe

竹谷政彦, 永井大樹

宇宙科学技術連合講演会講演集　2013/10/09
Thermal Analysis of Mars Airplane Balloon Experiment-1 (MABE1)

永井大樹, 大丸拓郎

宇宙科学技術連合講演会講演集　2013/10/09
Experimental Study on Startup Behavior considering Gravity Effect of a Miniature Loop Heat Pipe

Nagai, H, Tamamura, H, Nagano, H, Ogawa. H

Proceedings of The 17th International Heat Pipe Conference　2013/10

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Paper No.78
Operational characteristics of the Oscillating Heat Pipe with Non-Condensable Gas

Takurou Daimaru, Hiroki Nagai

43rd International Conference on Environmental Systems　2013/09

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In this study, the effects of Non-Condensable Gas (NCG) on the Oscillating Heat Pipe (OHP) were investigated. The OHP was made of copper capillary tube and the turn number of the OHP was 16. The employed working fluid was ethanol, and argon gas was used as the NCG. Experiments were conducted on 4 different NCG volume conditions. Temperature and inner pressure of OHP was measured over a heat input range from 40W to 180W. The results of this study have suggested that the operating characteristics of OHP were affected by the NCG and the thermal resistance of OHP was increased.
Preliminary design and thermal analysis of a miniature mars airplane thermal control system

Takurou Daimaru, Hiroki Nagai

43rd International Conference on Environmental Systems　2013/09

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Mars is the next milestone in our exploration of the solar system. The presence of an atmosphere on Mars signifies that an airplane could travel in its atmosphere using the aerodynamic forces of flight. An airplane offers the possibility to obtain high-resolution data on a regional scale of several hundreds to thousands of kilometers, which cannot be achieved with rovers or satellites. A conceptual design of a 3.5 kg fixed-wing, propeller-driven, deployable miniature airplane was developed by Tohoku University and ISAS/JAXA to study the feasibility of a Mars Airplane. This paper will describe the preliminary design and analysis of the Mars Airplane's thermal control system for its flight through the Martian atmosphere. Initial analyses are discussed and results of thermal control development are presented which detail the design process for the thermal control system.
Characteristics of low-Reynolds number airfoils in a mars wind tunnel

Hiroki Nagai, Keisuke Asai, Daiju Numata, Tetsuya Suwa, Masayuki Anyoji

51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2013　2013/08/19

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The aerodynamic characteristics of thin airfoils at low Reynolds number were investigated in a Mars Wind Tunnel at Tohoku University. The lift and the drag of five airfoils (NACA 0012, 5% flat plate, 1% flat plate, 3% circular arc, 6% circular arc) were investigated by using a two-component balance system at Re=1.1×10 4 and Mach number about 0.2. Also, Pressure-Sensitive Paint technique was used to measure pressure distributions around the airfoils. The results obtained by the balance system show that The maximum lift to drag ratio of the 3% circular arc is the largest among the airfoils tested in this study. And the results of PSP measurement show that the lift slope becomes large where a bubble with relatively short length appears on the airfoil surface, and the thicker airfoil has longer separation bubble than the thin airfoil at the same angle of attack. Furthermore, the airfoil surface having large curvature, the range of angles of attack where the separation bubble exists becomes narrow because the appearance of a separation bubble by an increase of angle of attack is delayed. © 2013 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
Development of ultrafast-response anodized-aluminum pressure-sensitive paints

Shota Fujii, Daiju Numata, Hiroki Nagai, Keisuke Asai

51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2013　2013/08/19

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In order to apply Pressure-Sensitive Paint (PSP) to unsteady shock-wave phenomena, Anodized-Aluminum PSP (AA-PSP) with ultrafast response was fabricated and its response time to a step pressure change was evaluated by using a shock tube. Phosphoric acid was used as electrolyte in anodization and the anodic alumina with pore diameter as large as 160 nm was successfully fabricated. The improved AA-PSP achieved a response with the time constant of 0.35 μs. This is the fastest PSP ever reported. We applied this AA-PSP to interactions of a moving shock wave with a circular cylinder. The results show that the improved AA-PSP can visualize the shock reflections and the shock diffractions with the ever-highest spatial and temporal resolution. © 2013 by Keisuke Asai.
Non-Condensable Gas effect in Oscillating Heat Pipe

Daimaru, T, Nagai, H

Proceedings of 43rd International Conference on Environmental Systems　2013/07

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AIAA 2013-3329
Numerical Study on Shock Wave Interaction over Compression Corner with 30 deg. in Hypersonic Flow

Kuramoto, T, Tsuboi, N, Nagai, H, Asai, K

Proceedings of 29th International Symposium on Shock Waves　2013/07

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Paper # 0246-000035
Operational characteristics of the Oscillating Heat Pipe with non-condensable gas

Daimaru, T, Nagai, H

Proceedings of 43rd International Conference on Environmental Systems　2013/07

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AIAA 2013-3329
Preliminary design and thermal analysis of a miniature Mars airplane thermal control system

Daimaru, T, Nagai, H

Proceedings of 43rd International Conference on Environmental Systems　2013/07

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AIAA 2013-3349
Experimental Investigation of Non-condensable Gas effects on the Oscillating Heat Pipe

Daimaru, T, Nagai, H

Proceedings of 29th International Symposium on Space Technology and Science　2013/06/04

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2013-o-4-18
Dynamic Behaviour of Mars Airplane with Folded-Wing Deployment

Fujita, K, Motoda, Y, Nagai, H

Proceedings of 29th International Symposium on Space Technology and Science　2013/06/04

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2013-k-07
Propeller Slipstream Interference with Wing Aerodynamic Characteristics of Mars Airplane at Low Reynolds Number

Makino, F, Nagai, H, Asai, K

Proceedings of 29th International Symposium on Space Technology and Science　2013/06/04

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2013-k-10
Numerical Simulation of Startup Behavior of Loop Heat Pipes with Secondary Wick

Magome, K, Taketani, M, Nagai, H

Proceedings of 29th International Symposium on Space Technology and Science　2013/06

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2013-o-4-1
Development of Ultrafast Response Anodized Aluminum Pressure-Sensitive Paints

Fujii, S, Numata, D, Nagai, H, Asai, K

Proceedings of 51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition　2013/01/07

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AIAA 2013-0485
Characteristics of Low-Reynolds Number Airfoils in a Mars Wind Tunnel

Nagai, H, Asai, K, Numata, D, Suwa, T, Anyoji, M

Proceedings of 51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition　2013/01/07

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AIAA 2013-0073
Heat Transfer Performance of Oscillating Heat Pipe by Difference of Surface Characteristics

Hiroki Nagai, Takamu Kanayama, Takurou Daimaru

Proceedings of the 17th International Heat Pipe Conference　2013

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Paper No.79
Development of Temperature-Sensitive Paint with High Performance and Responsibility for Aerodynamic Heating Measurement

洞桐健人, 永井大樹

可視化情報学会誌 = ournal of the Visualization Society of Japan　2013
Compressibility effects on airfoil aerodynamics at low Reynolds number

Tetsuya Suwa, Kei Nose, Daiju Numata, Hiroki Nagai, Keisuke Asai

30th AIAA Applied Aerodynamics Conference 2012　2012/12/01

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The objective of this study is to clarify the Mach number effect on the aerodynamic characteristics of airfoils at low Reynolds number. In this study, we conducted airfoil tests using a flat plate and a triangular airfoil in the Mars Wind Tunnel at Tohoku University. Reynolds number was set at 3,000 and 10,000 and Mach number at 0.15, 0.5 and 0.7. Aerodynamic force and pressure distributions on the models were measured using a force balance and Pressure-Sensitive Paint (PSP). The results show that the compressibility effect has an effect to move the flow separation point backward and to delay a reattachment of separated shear layer on the airfoil. These effects reduce the lift and the maximum lift-drag ratio. © 2012 by Keisuke Asai.
Conceptual design of a miniature, propeller-driven airplane for mars

Koji Fujita, Hiroki Nagai, Keisuke Asai

50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition　2012/12/01

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Mars is the next milestone in our exploration of the solar system. The presence of an atmosphere on Mars signifies that an airplane could travel in its atmosphere using the aerodynamic forces of flight. The airplane allows for a platform that can cover a larger area of exploration than is currently available. A reconnaissance airplane offers the possibility to obtain high-resolution data on a regional scale of several hundreds to thousands of kilometers, which cannot be achieved with rovers or satellites. However, conventional airplanes cannot fly in Martian atmosphere due to its environment and constraints from transport to Mars. A conceptual design was developed by Tohoku University to study the feasibility of a Mars Airplane. This paper discusses the design rationale undertaken at Tohoku University to develop a conceptual design of a 3.5 kg fixed-wing, propeller-driven, deployable airplane for the Mars exploration, following a predetermined set of requirements and constraints tailored for a small scale scientific mission to Mars. The design process includes the optimization of the geometry of the airplane for cruising performance, a total mass build-up, 3-D CAD modeling, and trade-off studies. Copyright © 2012 by the American Institute of Aeronautics and Astronautics, Inc.
Conceptual Design with Aerial Deployment Mechanisms of Airplane for Mars

Fujita, K, Nagai, H, Asai, K

Proceedings of 2012 Asia-Pacific International Symposium on Aerospace Technology　2012/11/13

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Paper #1.7.4
Heat Transfer Performance of Oscillating Heat Pipe by Difference of Surface Characteristics

Nagai, H, Kanayama, T, Daimaru, T

Proceedings of The 17th International Heat Pipe Conference　2012/10
Experiment verification of Acoustic Feedback Loop around NACA0012 Airfoil at Low Reynolds Number

Sakai, N, Nagai, H, Asai, K, Ikeda, T, Atobe, T

Proceedings of 9th International Conference Fluid Dynamics　2012/09/19

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pp652-653
Development of Ultrafast Time Response Pressure-Sensitive Paint for Visualization of Shock Wave Phenomena

Fujii, S, Numata, D, Nagai, H, Asai, K

Proceedings of 9th International Conference Fluid Dynamics　2012/09/19

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GS1-34
Transient Analysis of Loop Heat Pipes with Secondary Wick

Magome, K, Taketani, M, Nagai, H

Proceedings of 9th International Conference Fluid Dynamics　2012/09/19

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pp.570-571
Development of Back Surface TSP Measurement Technique for Shock Interaction Aerodynamic Heating in High Enthalpy Flow

Nishigata, K, Nagai, H, Asai, K

Proceedings of 9th International Conference Fluid Dynamics　2012/09/19

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pp.648-649
Non-Condensable Gas effect in Oscillating Heat Pipe

Daimaru, T, Nagai, H

Proceedings of 9th International Conference Fluid Dynamics　2012/09/19

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pp.582-583
Response Time Evaluation of Temperature-Sensitive Paint

Horagiri, T, Nagai, H

Proceedings of 9th International Conference Fluid Dynamics　2012/09/19

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pp.598-590
Compressibility Effect on Aerodynamic Characteristics of Low Reynolds Number Airfoils

Suwa, T, Numata, D, Nagai H, Asai K

Proceedings of 9th International Conference Fluid Dynamics　2012/09/19

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OS11-70
Conceptual Design Method for a Mars Airplane: Formulation of Aerodynamic Characteristics at Low Reynolds Numbers

Fujita, K, Nagai, H, Asai, K

Proceedings of the 9th International Conference on Flow Dynamics　2012/09/19

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OS 11-8
J052011 PSP measurement of a Soccer Ball

SEO Kazuya, YORITA Daisuke, NAGAI Hiroki, ASAI Keisuke, ASAI Takeshi, ITO Shinichiro

Mechanical Engineering Congress, Japan　2012/09/09

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PSP measurement of a non-spinning soccer ball has been carried out. It is found that the seam of the ball is the trigger for initiating low pressure. The depth of the seam on the ball was measured. It is found that the depth of the seam on the ball affects the critical Reynolds number. The deeper the depth is designed, the smaller the critical Reynolds number is achieved.
Compressibility Effect on Airfoil Aerodynamics at Low Reynolds Number

Suwa, T, Numata, D, Nagai, H, Asai, K

Proceedings of AIAA Fluid Dynamics and Co-located Conferences and Exhibit　2012/06/25

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AIAA 2012-3029
Characterization of frequency response of pressure-sensitive paints

Tamao Sugimoto, Sakiko Kitashima, Daiju Numata, Hiroki Nagai, Keisuke Asai

50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition　2012/06/20

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In this study, the frequency characteristics of fast-responding Pressure-Sensitive Paints(PSP) were evaluated by using a device based on an acoustic tube. The gain and phase characteristics of two different types of fast-responding PSP, Polymer-Ceramic PSP and Anodized-Aluminum PSP, were measured over the frequency range from 0.15 to 10 kHz and their dependence on binder, luminophore and temperature were investigated. From the measured frequency characteristics, the transfer functions were evaluated and the factors governing the time response of each PSP were estimated. The results of this study have suggested that luminophore molecules are distributed near the surface of PC-PSP and on the other hand are adsorbed inside the pores of AA-PSP. © 2012 by Keisuke Asai.
Analysis of Shock-Wave Structures in a Supersonic Biplane by Focusing Schlieren Technique

HAGIWARA Masumi, NAGAI Hiroki, NUMATA Daiju, ASAI Keisuke

日本航空宇宙学会論文集 = Journal of the Japan Society for Aeronautical and Space Sciences　2012/06/05
812 Three-Dimensional Numerical Study of Flow around Compression Corner with 30 Degrees in Hypersonic Flow:Effects of Plate Width

KURAMOTO Takeshi, MUTOH Daiki, TSUBOI Nobuyuki, NAGAI Daiki, ASAI Keisuke

日本機械学会九州支部講演論文集　2012/03/16
Characterization of Frequency Response of Pressure-Sensitive Paints International-presentation

Sugimoto, T, Kitashima, S, Numata, D, Nagai, H, Asai, K

50th AIAA Aerospace Sciences Meeting　2012/01/09

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AIAA2012-1185
Conceptual Design of a Miniature, Propeller-Driven Airplane for Mars International-presentation

Fujita, K, Nagai, H, Asai, K

50th AIAA Aerospace Sciences Meeting　2012/01/09

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AIAA 2012-0847
先進型熱制御デバイスループヒートパイプの研究開発

岡本篤, 畠中龍太, 川崎春夫, 杉田寛之, 小川博之, 長野方星, 大串哲朗, 村上正秀, 永井大樹

第12回宇宙科学シンポジウム　2012/01/06
火星表面探査用航空機の研究開発

大山聖, 永井大樹, 竹内伸介, 得竹浩, 山田和彦, 豊田裕之, 砂田茂, 小川博之, 戸田和朗, 元田敏和, 藤田和央, 安部隆士, 米本浩一, 藤井孝藏, 浅井圭介, 火星探査航空機

第12回宇宙科学シンポジウム　2012/01/06
低Re数翼の空力特性に対する乱流装置の効果

中村勘太, 依田大輔, 沼田大樹, 永井大樹, 浅井圭介

日本航空宇宙学会北部支部2012年講演会　2012/01/06
Aerodynamic Behavior of a Soccer Ball

瀬尾和哉, 依田大輔, 永井大樹

可視化情報学会誌 = ournal of the Visualization Society of Japan　2012
極超音速流れにおける30°ランプ周りの衝撃波干渉に関する数値解析 : 熱流束に与える影響

倉本健史, 坪井伸幸, 永井大樹

日本航空宇宙学会西部支部講演会講演集　2012
MELOS1に向けた火星探査飛行機の多目的設計探査

大山聖, 米本浩一, 竹内伸介, 得竹浩, 永井大樹, 砂田茂, 大槻真嗣

平成23年度宇宙航行の力学シンポジウム　2011/12/19
テフロンウィックを用いたマルチエバポレータ・マルチコンデンサ型ループヒートパイプの設計および評価

奥谷翔, 長野方星, 小川博之, 岡崎俊, 永井大樹

平成23年度宇宙航行の力学シンポジウム　2011/12/19
セカンダリウィック形状によるループヒートパイプ性能への影響

眞籠耕平, 永井大樹

平成23年度宇宙航行の力学シンポジウム　2011/12/19
表面特性の違いによる自励振動ヒートパイプの高性能化への実験的研究

金山貴夢, 大丸拓郎, 永井大樹

平成23年度宇宙航行の力学シンポジウム　2011/12/19
飛行機で見る火星の世界

文化フォーラム in 仙台「見えない宇宙をみる科学の眼」　2011/12/18
Supersonic wind tunnel experiment on aerodynamic characteristics and winglets effects of the tapered supersonic biplane

Takashi Fujisono, Hiroshi Yamashita, Atsushi Toyoda, Hiroki Nagai, Keisuke Asai, Takashi Matsuno, Hiromitsu Kawazoe, Shinkyu Jeong, Shigeru Obayashi

ASME-JSME-KSME 2011 Joint Fluids Engineering Conference, AJK 2011　2011/12

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The aerodynamic characteristics and the effects of tip plates of a tapered supersonic biplane wing during the starting process have been investigated through Experimental and Computational Fluid Dynamics (EFD/CFD). Three types of the wing model were used: without tip plate (type-N); with the tip plate which covers only the aft-half of the wing tip (type-A); with the tip plate which covers the entire wing tip (type-B). Experiment was conducted in the supersonic blowdown wind tunnel with 600 mm × 600 mm cross section located at the High-speed Wind Tunnel Facility of Institute of Space and Astronautical Science (ISAS/JAXA). The flow conditions covered from M ∞ = 1.5 to 1.9 with increments of 0.1. Pressure-Sensitive Paint was applied to measure pressure distributions on the surface of the wing. CFD simulations were conducted to compare with experiments and to investigate effects of the Mach numbers in detail. The tapered biplane wing without the tip plate was found to start between M ∞ =1.8 and 1.9. The difference of the starting Mach numbers between type-N and type-A was small. On the other hand, the starting Mach number of type-B was about 0.05 higher than that of type-N. Copyright © 2011 by ASME.
低レイノルズ数領域における石井翼の空力特性評価

安養寺正之, 野々村拓, 大山聖, 藤井孝藏, 野瀬慶, 沼田大樹, 永井大樹, 浅井圭介

第55回宇宙科学技術連合講演会　2011/12/01
火星大気風洞を用いた低レイノルズ数領域における薄翼の空力特性の研究

永井大樹, 伊田真悟, 野瀬慶, 安養寺正之, 沼田大樹, 浅井圭介

第55回宇宙科学技術連合講演会　2011/12/01
セカンダリウィック形状によるループヒートパイプ性能への影響

眞籠耕平, 永井大樹

第55回宇宙科学技術連合講演会　2011/12/01
Heat Transfer Characteristics of Oscillating Heat Pipe by Difference of Surface Characteristic

Kanayama, T, Daimaru, T, Nagai, H, Ogawa, H

Proceedings of the Eighth International Conference on Flow Dynamics　2011/11/09

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OS12-41
Secondary Wick Effect for Performance of Loop Heat Pipes International-presentation

Magome, K, Nagai, H

Eighth International Conference on Flow Dynamics　2011/11/09

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OS12-40
Heat Transfer Characteristics of Oscillating Heat Pipe by Difference of Surface Characteristics International-presentation

Eighth International Conference on Flow Dynamics　2011/11/09
Development of Temperature-Sensitive Paint for High-Temperature Measurement International-presentation

Sawamura, R, Nishigata, K, Nagai, H, Asai, K

Eighth International Conference on Flow Dynamics　2011/11/09

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OS12-42
High-accuracy Calculation for Aerodynamic Heating Using Temperature-Sensitive Paint International-presentation

Nishigata, K, Sawamura, R, Nagai, H, Asai, K

Eighth International Conference on Flow Dynamics　2011/11/09

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OS12-39
Unsteady Aerodynamic Experiment of NACA0012 Airfoil at Low Reynolds Number International-presentation

Nose, K, Sakai, N, Numata, D, Nagai, H, Asai, K, Ikeda, T, Atobe, T

Eighth International Conference on Flow Dynamics　2011/11/09

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OS3-2
Aerial Deployment Test of a Small UAV for Mars Exploration Flight International-presentation

Fujita, K, Nagai, H, Asai, K, Tokutake, H

Eighth International Conference on Flow Dynamics　2011/11/09

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OS6-9
Conceptual Examination of a Small UAV for Mars Exploration Flight International-presentation

Fujita, K, Nagai, H, Asai, K

Eighth International Conference on Flow Dynamics　2011/11/09

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OS12-7
Evaluation of Aerodynamic Characteristics of a Triangular Airfoil at Low Reynolds Number and High-Subsonic Mach Number International-presentation

Suwa, T, Nose, K, Numata, D, Nagai, H, Asai K

Eighth International Conference on Flow Dynamics　2011/11/09

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OS12-64
Comparison of Aerodynamic Data of a Wing Tested in Wind Tunnels at Low Reynolds Numbers International-presentation

Koike, M, Nagai, H, Yonemoto, K, Asai, K

Eighth International Conference on Flow Dynamics　2011/11/09

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OS6-2
Design of A Propeller of An Airplane on Mars International-presentation

Hayashida, T, Sunada, S, Ishida, R, Kaneko, K, Suwa, T, Nagai, H, Asai, K, Goto, Y, Yonezawa, K, Tsujimoto, Y

Eighth International Conference on Flow Dynamics　2011/11/09

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OS6-10
Aerodynamics Characteristics of Ishi Airfoil at Low Reynolds Numbers International-presentation

Anyoji, M, Nonomura, T, Oyama, A, Fujii, K, Nose, K, Numata, D, Nagai, H, Asai, K

Eighth International Conference on Flow Dynamics　2011/11/09

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OS6-11
Experimental Study of Low-Reynolds-Number Aerodynamic Characteristics of Thin Airfoils in a Mars Wind Tunnel International-presentation

Nagai, H, Ida, S, Nose, K, Anyoji, M, Numata, D, Asai, K

Eighth International Conference on Flow Dynamics　2011/11/09

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OS6-12
”世界初”の飛行機による火星探査の実現に向けて！

第14回新生流体科学セミナー　2011/11/04
非定常感圧塗料計測の動的風洞試験への適用

原達矢, 阿部弘之, 依田大輔, 沼田大樹, 永井大樹, 浅井圭介

第7回学際領域における分子イメージングフォーラム　2011/11/02
高速非定常流体現象解明のための超高速応答型感圧塗料の開発

藤井祥太, 沼田大樹, 永井大樹, 浅井圭介

第7回学際領域における分子イメージングフォーラム　2011/11/02
火星探査航空機の空力性能

永井大樹, 浅井圭介, 大山聖, 野々村拓, 藤井孝藏, 米本浩一, 越智廣志, 小池勝, 岡本正人, 安養寺正之

第49回飛行機シンポジウム　2011/10/27
火星探査飛行機の高々度飛行試験計画

大山聖, 永井大樹, 得竹浩, 竹内伸介, 豊田裕之, 藤田昴志, 安養寺正之, 元田敏和, 米本浩一, 浅井圭介, 藤井孝藏, 火星探査航空機WG

2011年度大気球シンポジウム　2011/10/06
火星に飛行機を飛ばそう

第19回科学講演会　2011/09/04
ループヒートパイプの作動特性に対する重力加速度の影響

永井大樹, 玉村大道, 真籠耕平, 長野方星, 小川博之

日本混相流学会年会講演会2011　2011/08/06
"SUPERSONIC WIND TUNNEL EXPERIMENT ON AERODYNAMIC CHARACTERISTICS AND WINGLETS EFFECTS OF THE TAPERED SUPERSONIC BIPLANE

Fujisono, T, Yamashita, H, Toyoda, A, Nagai, H, Asai, K, Matsuno, T, Kawazoe, H, Jeong, S, Obayashi, S

AJK2011-15015, Proceedings of ASME-JSME-KSME Joint Fluids Engineering Conference 2011, AJK2011-FED　2011/07/24
感圧塗料を用いた非定常空気力計測

依田大輔, 山﨑真一, 沼田大樹, 永井大樹, 浅井圭介

第39回可視化情報シンポジウム,　2011/07/18
感温塗料による空力加熱計測手法の高精度化

西潟一樹, 澤村亮輔, 永井大樹, 浅井圭介

第39回可視化情報シンポジウム,　2011/07/18
極低温キャビテーション試験に適用可能な感温塗料の開発と評価

藤井祥太, 新井山一樹, 永井大樹, 浅井圭介

第39回可視化情報シンポジウム,　2011/07/18
蛍光油膜法による翼面はく離流れのイメージング

荻田力, 中村勘太, 依田大輔, 沼田大樹, 永井大樹, 浅井圭介

日本航空宇宙学会第43回流体力学講演会　2011/07/07
低レイノルズ数・高亜音速領域における三角翼型の空力特性の評価

諏訪哲也, 野瀬慶, 沼田大樹, 永井大樹, 浅井圭介

日本航空宇宙学会第43回流体力学講演会　2011/07/07
Thermal vacuum testing of a small loop heat pipe with a PTFE wick for spacecraft thermal control International-presentation

The 28th International Symposium on Space Technology and Science　2011/06/07
Conceptual Design of Mars Airplane International-presentation

The 28th International Symposium on Space Technology and Science　2011/06/07
PSP Measurement of Pressure Distribution on a Cambered Airfoil for Mars Exploration Airplane International-presentation

The 11th Asian Symposium on Visualization　2011/06/06
Evaluation of Temperature-Sensitive Paint using Thermographic Phosphor by Hypersonic Aerodynamic Heating International-presentation

The 11th Asian Symposium on Visualization　2011/06/06
Evaluation of Transfer Function of Pressure-Sensitive Paint for Unsteady Flow Measurement International-presentation

The 11th Asian Symposium on Visualization　2011/06/06
Evaluation of Transfer Function of Pressure-Sensitive Paint for Unsteady Flow Measurement

T. Sugimoto, D. Yorita, D. Numata, H. Nagai, K. Asai

Proceedings of the 11th Asian Symposium on Visualization　2011/06/04

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ASV11-12-07
Evaluation of Temperature-Sensitive Paint using Thermographic Phosphor by Hypersonic Aerodynamic Heating

Sawamura, R, Nishigata, K, Nagai, H, Asai, K

Proceedings of the 11th Asian Symposium on Visualization　2011/06/04

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ASV11-11-19
PSP Measurement of Pressure Distribution on a Cambered Airfoil for Mars Exploration Airplane

Nose, K, Anyoji, M, Numata, D, Nagai, H, Asai, K

Proceedings of the 11th Asian Symposium on Visualization　2011/06/04

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ASV11-11-10
火星探査用小型飛行機の検討

大山聖, 永井大樹, 竹内伸介, 豊田裕之, 砂田茂, 得竹浩, 小川博之, 戸田和朗, 小池勝, 元田敏和, 藤田和央, 火星探査航空機

日本航空宇宙学会第42期年会講演会　2011/04/14
Planetary Locomotion-惑星探査の新しい可能性

浅井圭介, 永井大樹

日本航空宇宙学会第42期年会講演会　2011/04/14
火星大気風洞を用いた空力実験

安養寺正之, 野瀬慶, 伊田真悟, 沼田大樹, 永井大樹, 浅井圭介

日本航空宇宙学会第42期年会講演会　2011/04/14
非定常衝撃波現象への適用を目指した超高速応答型感圧塗料の開発

藤井祥太, 沼田大樹, 永井大樹, 浅井圭介

平成23年度衝撃波シンポジウム　2011/03/07
Experimental study on dynamic instability of re-entry capsule-shaped body using pressure sensitive paint

Daisuke Sugimoto, Hiroki Nagai, Keisuke Asai, Koju Hiraki

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition　2010/12/13

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Re-entry capsule with flat body shapes tends to be dynamically unstable in the transonic speed range, and sometimes fall into self-exited pitching oscillation. In this study, the Phase Lock Method with a fast-responding Pressure-Sensitive Paint (PSP) has been employed to visualize unsteady pressure distribution on a capsule model undergoing the pitching motion. In addition, the pressure fluctuation was measured using time-series high-speed camera PSP images. Analysis of the PSP results together with pitch angle measurement has revealed that the phase delay of the base surface pressure acts as dynamically unstable moment in the low pitch angles. © 2010 by the American Institute of Aeronautics and Astronautics, Inc.
Characteristics of the Mars Wind Tunnel at Tohoku University in CO <inf>2</inf> operation mode

M. Anyoji, S. Ida, K. Nose, D. Numata, H. Nagai, K. Asai

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition　2010/12/13

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The Mars Wind Tunnel at Tohoku University is a low-density tunnel that can simulate Martian atmospheric flight condition. Up to the present, this tunnel has been operated using air as the working gas. To expand the capability of this tunnel and to study the effects of compressibility on airfoil performance at low Reynolds number, a modification has been made to allow the tunnel to be operated using CO 2 , that is the main constituent of the Martian atmosphere. In this study, the operational characteristics as well as the flow quality in the test section are investigated in CO 2 mode and compared with the results obtained in air mode. It is found that a higher Mach number can be achieved in CO 2 mode than in air mode as the speed of sound decreases with the molecular weight. No negative effect of CO 2 such as freezing inside the ejector nozzles has been observed over the entire operational conditions of the tunnel. Mach number profile is found to be uniform over a wide range of Reynolds number except inside the boundary layers on the walls. The static pressure gradient along the test section is almost zero at the total pressure of lkPa. These results prove that the Mars Wind Tunnel has a capability to simulate the real Martian atmospheric condition.
Unsteady PSP technique for measuring naturally-disturbed periodic phenomena

D. Yorita, H. Nagai, K. Asai, T. Narumi

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition　2010/12/13

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To understand unsteady flow phenomena, it is important to measure time-resolved pressure variations with high spatial resolution. Pressure Sensitive Paint (PSP) has a capability of providing high-resolution pressure images, but the Signal-to-Noise Ratio (SNR) is not high enough to analyze unsteady flow structures in low-speed flow. The phase-lock method is often applied to PSP measurement of periodic flow phenomena, but it is difficult to apply this technique to unsteady flow containing natural disturbances in amplitude and phase. To solve this problem, we propose a new type of phase-lock method in which images of unsteady pressure field are phase-locked using a trigger signal processed with signal conditioning techniques such as band-pass filtering and signal differentiation. The effectiveness of this method was verified using simulated signal and applied to low-speed wind tunnel testing of a 3-D square cylinder model. As a result, we could obtain time-resolved unsteady pressure field on the side of the square cylinder due to periodic Karman vortex shedding. The fluctuating pressures were found to be high at the lower part of the side wall, that is in good agreement with the pressure transducers data. © 2010 by the American Institute of Aeronautics and Astronautics, Inc.
Low Reynolds number airfoil testing in a Mars Wind Tunnel

Masayuki Anyoji, Kei Nose, Shingo Ida, Daiju Numata, Hiroki Nagai, Keisuke Asai

40th AIAA Fluid Dynamics Conference　2010/12/02

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The aerodynamic characteristics of a 5% flat plate and NACA0012-34 airfoil in low Reynolds number (Re=0.43×10 4 ∼4.1×10 4 ) and high subsonic flow (M=0.1∼0.6) were investigated in the Mars Wind Tunnel (MWT) at Tohoku University. A two-component balance system and Pressure-Sensitive Paint (PSP) technique have been developed to measure the lift and drag forces and pressure profiles on the model. For the flat plate, Mach number effect does not have much effect on its aerodynamic performance while Reynolds number affects the lift slope and the drag characteristics. On the contrary, for NACA0012-34 airfoil, both Reynolds and Mach number effects become more prominent. The lift curves are highly nonlinear and the drag polars are affected by behaviors of a laminar separation bubble in trans-critical condition. A comparison of the results obtained at different Mach numbers has suggested that the compressibility has an effect to stabilize separated shear layer. It has been verified by this experiment that the MWT can offer a unique capability to investigate airfoil performance in low Reynolds number and high Mach number flow. © 2010 by the American Institute of Aeronautics and Astronautics, Inc.
Development of an experimental small loop heat pipe with PTFE wick

Hosei Nagano, Hosei Nagano, Fuyuko Fukuyoshi, Fuyuko Fukuyoshi, Hiroyuki Ogawa, Hiroyuki Ogawa, Hiroki Nagai, Hiroki Nagai

40th International Conference on Environmental Systems, ICES 2010　2010/12

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This paper reports development of an experimental small LHP with PTFE wick. PTFE porous materials with 0.8 - 2.2 μm pore radius were fabricated and the basic properties were evaluated. An experimental small LHP with the PTFE wicks was designed and tested in an atmospheric condition. A PTFE wick with 1.2 μm pore radius was used to demonstrate the loop performance. The test results showed excellent operating characteristics of the LHP. © 2010 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
1501 Pressure-Sensitive Paint Measurement of Unsteady Pressure Fields induced by Karman Vortex

YORITA Daisuke, NUMATA Daiju, NAGAI Hiroki, ASAI Keisuke

Fluids engineering conference ...　2010/10/29

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To understand unsteady flow phenomena around a body, it is important to measure time-resolved surface pressure distributions with high spatial resolution. Pressure Sensitive Paint (PSP) has a capability of providing high-resolution pressure images. In this study, we propose a new PSP technique to obtain time-resolved surface pressure distributions by using conditional sampling of time-series PSP images. To obtain high SNR data, the high-speed camera images are phase-averaged after image acquisition, using a simultaneously-measured pressure transducer data to detect a phase of each image. This method allows us to obtain high SNR images at arbitrary phase of the periodic phenomena using a simplify measurement system and image processing. The effectiveness of the present method was evaluated by applying it to a 3-D square cylinder in low-speed wind tunnel testing. As a result of this experiment, we could obtain time-resolved unsteady pressure images around the square cylinder caused by periodic vortex shedding.
Measuring Unsteady Low-Speed Flow Phenomena by Using a Time-Series Analysis of Pressure-Sensitive Paint Images

Yorita, D, Numata, D, Nagai, H, Asai, K

The 14th International Symposium on Flow Visualization　2010/06

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ISFV14-9E-1
Development of Aerodynamic Heating Measurement Technique Using Temperaturesensitive Paint in Hypersonic Flow

Ha, S, Sawamura, R, Nagai, H, Asai, K

The 14th International Symposium on Flow Visualization　2010/06

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ISFV14-7D-2
Visualization of a Three-Dimensional Shock-Wave Structures in a Supersonic Busemann Biplane by Sharp Focusing Schlieren System and PSP Measurement

Hagiwara, M, Nagai, H, Numata, D, Asai, K

The 14th International Symposium on Flow Visualization　2010/06

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ISFV14-7B-2
Imaging Measurement of Skin Friction Field around Bluff Body Using Luminescent Oil Film Technique

Kakuta, T, Koyama, A, Yorita, D, Numata, D, Nagai, H, Asai, K, Woodiga, S.A, Liu, T

The 14th International Symposium on Flow Visualization　2010/06

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ISFV14-5D-2
Development of Pressure-Sensitive Paint Technique for Surface Pressure Measurement in a Mars Wind Tunnel

Ono, T, Anyoji, M, Ida, S, Nose, K, Numata, D, Nagai, H, Asai, K

The 14th International Symposium on Flow Visualization　2010/06

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ISFV14-4D-5
Characteristics of Thermal Anemometers at Low-Pressure Condition in a Mars Wind Tunnel

D. Numata, M. Anyoji, Y. Sugino, H. NAGAI, K. ASAI

49th AIAA Aerospace Science Meeting and Exhibit　2010/01

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AIAA-2011-1166
Aerodynamic Measurements in the Mars Wind Tunnel at Tohoku University

M. Anyoji, K. Nose, S. Ida, D. Numata, H. Nagai, K. Asai

49th AIAA Aerospace Science Meeting and Exhibit　2010/01

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AIAA-2011-0852
Experimental Study of Heat Transfer Measurement using Temperature-Sensitive Paint for High-Temperature Application in Hypersonic Flow

Hiroki Nagai, Ryosuke Sawamura, Keisuke Asai

49th AIAA Aerospace Science Meeting and Exhibit　2010/01

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AIAA-2011-0850
Experimental Study on Dynamic Instability of Re- Entry Capsule-Shaped Body using Pressure- Sensitive Paint

SUGIMOTO, D, NAGAI, H, ASAI, K, HIRAKI, K

48th AIAA Aerospace Science Meeting and Exhibit　2010/01

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AIAA-2010-0320
Unsteady PSP Technique for Measuring Naturally-Disturbed Periodic Phenomena

YORITA, D, NAGAI, H, ASAI, K, NARUMI, T

48th AIAA Aerospace Science Meeting and Exhibit　2010/01

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AIAA-2010-0307
Study of temperature-sensitive-paint consisting of phosphor and ceramic compound for high temperature

澤村亮輔, 永井大樹, 沼田大樹

Journal of the Visualization Society of Japan　2010
A fundamental characteristic and temperature controllability of a

FUKUYOSHI Fuyuko, NAGANO Hosei, OGAWA Hiroyuki, NAGAI Hiroki

Proceedings of National Heat Transfer Symposium　2010

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ループヒートパイプ（LHP）は，その熱輸送性能や搭載性が利点となる熱制御デバイスである．本実験ではミッション機器への応用も視野に入れて小型LHPに着目し，その動作特性を解明するためPTFE多孔質を用いた100W級の小型LHPを製作した．そして，熱負荷に対する動作温度の関係など基本性能を取得した．また，熱電変換素子によりリザーバの温度制御を行い，LHP動作温度の制御特性について実験を行い，リザーバ制御の有用性について実験的に示すことができた．
W0503-(2) 機能性分子センサーを用いた極限環境下における熱流体計測法(【W0503】EFDワークショップ『PSPによる表面情報の可視化計測』,ワークショップ)

永井大樹

年次大会講演資料集　2010
Development of low density wind tunnel to simulate atmospheric flight on Mars

M. Anyoji, H. Nagai, K. Asai

47th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition　2009/12/01

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A new type of wind tunnel that can simulate airfoil flow in the Mars atmosphere has been designed and constructed at Tohoku University. This wind tunnel is driven by ejector and designed to simulate low-density Martian atmosphere consisting of CO 2 . The preliminary performance tests were conducted using air to investigate the operating envelop of the tunnel. It was demonstrated that this wind tunnel could cover the Reynolds number range from 10 4 to 10 5 and the Mach number range up to 0.71, allowing us to simulate low Reynolds number and high subsonic flow on Mars airplanes. Calibration tests were also conducted to investigate the flow characteristics in the test section. It was confirmed that the flow was kept uniform in the test section even when the total pressure was 1 kPa. There were significant effects of the boundary layer development on static pressure gradient along the test section. It was found that these effects of boundary layers could be corrected by inclining both the upper and lower walls of the test section. Copyright © 2009 by the American Institute of Aeronautics and Astronautics, Inc.
Heat flux measurement techniques over the protuberance at the hypersonic flow of Mach 7

Hyoung Jin Lee, In Seuck Jeung, Bok Jik Lee, Seong Lyong Kim, Insun Kim, Osamu Imamura, Kojiro Suzuki, Koji Okamoto, Seungwon Ha, Hiroki Nagai, Keisuke Asai

16th AIAA/DLR/DGLR International Space Planes and Hypersonic Systems and Technologies Conference　2009/12/01

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An experimental investigation has been conducted on the aerodynamic heating caused by an object protruding from a flat plate at hypersonic flows of Mach 7. Three different experimental techniques are applied to measure the heat flux and temperature over the protuberance, using two types of hypersonic wind tunnels, namely, blowdown and impulse types. This paper presents the experimental techniques needed for use in hypersonic tunnels focusing on issues such as heat flux measurement techniques, as well as the measurement of detailed experimental data. It was confirmed that the data set agree well through the comparison of data results. A large separation region is observed in front of the protuberance with that region being very sensitive to the height of the protuberance and the length of the flat plate. These flow features affect the aerodynamic heating over the protuberance. Basically, the measured heat flux is large when the height of the protuberance is large and the length of the flat plate is long. Also, the heat flux measurements at the upper positions are larger than at the lower positions. For high protuberances, a severe jump in the heat flux is observed, from about 0.6∼0.7 of the height of the protuberances. However, when the protuberance is sufficiently short, a rise in the heat flux is rarely observed as the protuberance is submerged totally under the separation region upstream from the protuberance. Copyright © 2009 by the American Institute of Aeronautics and Astronautics, Inc.
0604 Three-Dimensional Effects on Surface Heat Flux of a Blunt-Nosed Body with an Aerospike in Hypersonic Flow

TSUBOI Nobuyuki, NAGAI Hiroki, ASAI Keisuke

Fluids engineering conference ...　2009/11/06

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A blunt body in hypersonic flow is subjected to severe aerodynamic heating and drag. This is one of the most critical problems of designing the hypersonic vehicles such as Reusable Launch Vehicles(RLV). It is well known that the spiked-nose(aerospike)concept is effective to reduce aerodynamic drag on asymmetric blunt bodies in hypersonic flow. In this study, we investigated the heat flux distribution on a blunt-nosed body with an aerospike in hypersonic flow. The flow field around a blunt-nosed body is calculated by the full Navier-Stokes simulations to compare with the experimental data such as Schlieren photographs and TSP(Temperature Sensitive Paint)images. It was found that the heat flux distributions changes widely with the angle of attack. Moreover, the correlation between heat flux and the flow and the flow field exists due to the shock/shock interaction patterns for various angle-of-attacks.
Unsteady Pressure Distribution Measurement on a Square Cylinder using Pressure-Sensitive Paint

YORITA, D, NARUMI, T, NAGAI, H, ASAI, K

6th International Conference on Flow Dynamics　2009/11

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9-28
Skin-Friction Measurement of Flow around Bluff Body Using Luminescent Oil-Film Technique

KAKUTA, T, KOYAMA, A, YORITA, D, NUMATA, D, NAGAI, H, ASAI, K

6th International Conference on Flow Dynamics　2009/11

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9-11
Analysis of Shock-wave Structures in a Supersonic Busemann Biplane by Sharp Focusing Schlieren System

HAGIWARA, M, NAGAI, H, NUMATA, D, ASAI, K

6th International Conference on Flow Dynamics　2009/11

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9-24
Application of Temperature-Sensitive Paint to Heat Flux Measurement in High Temperature Gas Flow

HA S, SAWAMURA, R, SAKAMOTO, H, NAGAI, H, NUMATA, D, ASAI, K

6th International Conference on Flow Dynamics　2009/11

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2-5
Optical Fiber Sensor Capable of Measuring Pressure and Temperature from Luminescent Lifetime

Sugai, N, Yorita, D, Numata, D, Nagai, H, Asai, K

6th International Conference on Flow Dynamics　2009/11

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9-63
Evaluation of Supersonic Ejector Driving Performance under Low Pressure

ANYOJI, M, NUMATA, D, NAGAI, H, ASAI, K

6th International Conference on Flow Dynamics　2009/11

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9-67
Experimental Study on the Thermal Performance of a Miniature Loop Heat Pipe with Different Orientations

NAGAI, H, NAGANO, H, FUKUYOSHI, F, OGAWA, H

27th International Symposium on Space Technology and Science　2009/07

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2009-h-5
Surface heat flux visualization on a blunt-nosed body with an aerospike in hypersonic flow using Temperature-Sensitive Paint

NAGAI, H, HA, S, ASAI, K, TSUBOI, N, NAKAKITA, K

27th International Symposium on Space Technology and Science　2009/07

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2009-e-27
Three dimensional effect of a supersonic busemann biplane on start process

NAGAI, H, OYAMA, S, ASAI, K, FUJISONO, T, OBAYASHI, S

27th International Symposium on Space Technology and Science　2009/07

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2009-e-21
PSP Measurement of a Rugby Ball and Visualizing Pareto-optimal Solutions for a Fluctuating Punted Kick in Rugby

SEO Kazuya, YORITA Daisuke, NAGAI Hiroki

Journal of the Visualization Society of Japan　2009/07/01
Development and evaluation of pressure-sensitive paint applicable to surface pressure measurements in Mars Wind Tunnel

ONO Tadashi, NAGAI Hiroki, ASAI Keisuke

Journal of the Visualization Society of Japan　2009/07/01
Measurement Error and Accuracy Evaluation of Pressure Sensitive Paint Measurement in a Low-speed Flow

YORITA Daisuke, NAGAI Hiroki, ASAI Keisuke, TANAKA Shingo, ISHIDA Keitaro

Journal of the Visualization Society of Japan　2009/07/01
Development of Low Density Wind Tunnel to Simulate Atmospheric Flight on Mars

ANYOJI, M, NAGAI, H, ASAI, K

47th AIAA Aerospace Sciences Meeting　2009/01

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AIAA-2009-1517
「感圧塗料」光る色素で圧力をはかる(ヘッドライン:光を発する塗料) Invited

浅井圭介, 永井大樹

化学と教育　2009

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感圧塗料は,機能性化合物の分子薄膜をセンサーとして用い,その発光から物体表面での圧力場を画像化する技術である。これらのセンサーは,物体上の物理量を面情報として可視化するだけでなく,従来のセンサーが設置できないような局所や微小物体にも適用できる。本解説では,この感圧塗料の基礎と作り方,簡単なデモ実験の方法について解説し,最後に航空宇宙分野の研究開発に適用されている感圧塗料の実用例を紹介する。
Measurement Error and Accuracy Evaluation ofPressure Sensitive Paint Measurement in a Low-speed Flow

YORITA Daisuke, NAGAI Hiroki, ASAI Keisuke, TANAKA Shingo, ISHIDA Keitaro

Transactions of Visualization Society of Japan　2009
Development and evaluation of pressure-sensitive paint applicable to surface pressure measurements in Mars Wind Tunnel

ONO Tadashi, NAGAI Hiroki, ASAI Keisuke

Transactions of Visualization Society of Japan　2009
PSP Measurement of a Rugby Ball and Visualizing Pareto-optimal Solutions for a Fluctuating Punted Kick in Rugby

SEO Kazuya, YORITA Daisuke, NAGAI Hiroki

Transactions of Visualization Society of Japan　2009
Effect of Amount of Fluid Charge in Thermal Performance of Loop Heat Pipe

Onogawa Ei, Nagano Hosei, Fukuyoshi Fuyuko, Ogawa Hiroyuki, Nagai Hiroki

Proceedings of National Heat Transfer Symposium　2009

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民生および宇宙分野で省エネで高効率な熱輸送技術が強く求められている。本研究では、ウィックとよばれる多孔質材内で発生する毛細管力を利用したループヒートパイプ技術に着目し、その高性能化と実用化に向けた研究開発に取り組んでいる。本報告では作動流体のチャージ量変化に伴う熱特性変化を実験的に明らかにしたので報告する。
Active control of operating characteristics forloop heat pipe with thermoelectric converters

FUKUYOSHI FUYUKO, NAGANO HOSEI, OGAWA HIROYUKI, NAGAI HIROKI

Proceedings of National Heat Transfer Symposium　2009

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海外において次世代のスタンダードな熱制御技術として毛細管駆動型二相流体ループ（ループヒートパイプ）の研究開発が進められており、本研究では日本の将来の宇宙ミッションを見据え，100W級の小型ループヒートパイプに着目し研究を行っている。今回、ループヒートパイプのリザーバ/補償チャンバー（Compensation Chamber, CC）の温度制御に熱電交換モジュールを用いて、ループヒートパイプの動作特性について実験および評価を行ったので報告する。
Thermal performance evaluation by gravity effect of a miniature loop heat pipe

Nagai Hiroki, Nagano Hosei, Fukuyoshi Fuyuko, Ogawa Hiroyuki

Proceedings of National Heat Transfer Symposium　2009

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近年、惑星探査や月面着陸などミッションの高度化にともない、より高性能で複雑な熱制御技術が必要とされている。特に、熱環境が複雑に変動するミッションにおいて、衛星の熱設計を高温側および低温側で同時に満足できるような熱制御技術が重要である。そこで、アメリカをはじめ海外では次世代のスタンダードな熱制御技術として毛細管駆動型二相流体ループ（ループヒートパイプ：LHP）が開発されてきた。本研究では日本の将来の宇宙ミッションを見据え、100W級の小型LHPに着目し、これまでにその起動特性ならびに熱輸送特性の評価を行ってきた。今回は、このループヒートパイプの重力方向に対する実験および評価を行ったので報告する。
S0506-1-1 PSP measurement on an ellipsoid with seams : The effect of seam on the pressure distribution

SEO Kazuya, YORITA Daisuke, NAGAI Hiroki, Shiroishi Nana, ASAI Keisuke

The proceedings of the JSME annual meeting　2009

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In this paper, the effect of the seams of a rugby ball on the side force is described in order to show why the punted kick fluctuates during the flight. Measurement of the aerodynamic force on a non-spinning rugby ball reveals that the side force depends on the position of the seam as well as the angle of attack. It was found from PSP measurements that the seam of the ball is the trigger for initiating low pressure. The seam of the ball produces an asymmetrical pressure distribution on the sides. Therefore, a slower spinning ball fluctuates during flight.
S1904-2-1 Study of Global heat flux measurement technique in Hypersonic flow using Temperature-Sensitive Paint

NAGAI Hiroki, HA Seungwon, ASAI Keisuke

The proceedings of the JSME annual meeting　2009

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Heat flux measurement in a hypersonic wind tunnel is one of indispensable requirements for designing the next generation re-entry vehicle. Heat flux is usually calculated from a temporal change in temperature on the model surface. Temperature-Sensitive Paint (TSP) is a global temperature measurement technique based on photochemical reaction. In this study, TSP technique was applied to a hypersonic shock tunnel test and the measurement accuracy was investigated with a different TSP thickness. From that result, the optimum thickness of TSP was found to be 0.2μm. Then, the heat flux distribution of a blunt-nosed body with an aerospike was investigated by an optimized TSP thickness
S1904-1-1 Correlation between the Pressure Distributions on Re-entry Capsule Shaped Body and Dynamic Instability

SUGIMOTO Daisuke, NAGAI Hiroki, ASAI Keisuke, HIRAKI Koju

The proceedings of the JSME annual meeting　2009

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A fast responding Pressure-Sensitive Paint (PSP) using polymer/ceramic binder and image capturing technique called Phase Lock Method were used to visualize the unsteady pressure distributions on a capsule-shaped body undergoing the pitching motion. In addition, schlieren visualization using high-speed video camera was used to take a picture around the flowfield of the model, together with pitch angle measurement using a potentiometer. As a result, the strength and the location of vortices behind the capsule varies depending on the direction of the oscillating motion, and the base pressure distributions are related to the dynamic motion of the vortices from the edge of the capsule.
3306 Study to develop an Evaluation Method of Fluid Force Acting on High-Speed Trains

Terashima Osamu, Abe Yukinobu, Kodera Takeyuki, Nagai Hiroki, Asai Keisuke

The Transportation and Logistics Conference　2008/12/09

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One of the aerodynamic issues affecting high-speed trains is the flow-induced vibration of the tail car when cruising through a tunnel, which results in reduced passenger comfort. The objective of this study is to develop a method to evaluate the fluid force acting on high-speed trains. We conducted wind tunnel tests of a simplified train model using a flat plate to simulate the effect of the tunnel wall. Pressure transducers were used to measure unsteady pressure fluctuations on the tunnel wall, and Pressure Sensitive Paint (PSP) was applied to measure time-averaged surface pressure distribution on the train model. We also conducted Large Eddy Simulation (LES) for the same model and test conditions. The results indicated that by applying LES, we were also to reconstruct the spectrum of pressure fluctuation on the tunnel wall that we observed in the wind tunnel experiment.
Evaluation of plasma actuator performance in Martian atmosphere for applications to Mars airplanes

Masahiko Takagaki, Susumu Isono, Hiroki Nagai, Keisuke Asai

4th AIAA Flow Control Conference　2008/12/01

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The plasma actuator is considered as a promising control device for Mars airplanes. The Martian atmosphere is very thin and its major constituent is CO2. Therefore, we need to evaluate the plasma actuator performance under these conditions. In this study, the flow velocity field and the thrust produced by the plasma actuator were measured for various pressures and gas species. For this purpose, we applied the smoke wire method and calculated the induced flow velocity and the thrust using the image analysis method by Liu and Shen. It is found that the plasma actuator can induce the flow in CO2 at 1kPa which is condition of Mars atmosphere. Copyright © 2008 by the American Institute of Aeronautics and Astronautics, Inc.
Enhancement of pressure-sensitive paint emission using localized surface plasmon resonance for shock tunnel applications

Y. Miura, H. Nagai, K. Asai, K. Nakakita

46th AIAA Aerospace Sciences Meeting and Exhibit　2008/12/01

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To apply Pressure-Sensitive Paint (PSP) to unsteady or short-duration tests like hypersonic shock tunnels, we need to solve the two fundamental problems. First, polymer-based PSP shows slow time response so that the thickness of PSP film must be reduced to a submicron range. However, such a thin paint film displays a very low Signal-to-Noise Ratio (SNR) because the number of photons detected by a camera is reduced with film thickness. To solve these conflicting problems, it is required to develop a new PSP that emits strong luminescence even though its film thickness is thin enough for unsteady measurements. In this study, systematic experiments were conducted to explore the potential of using Localized Surface Plasmon Resonance (LSPR) of silver (Ag) nanoparticles to enhance the luminescent emission of polymer-based PSP. PSP coupons containing Ag nanoparticles of different sizes and concentrations were prepared and their luminescent intensities were compared. It was found that the luminescent intensity of PSP sample was enhanced about 3-fold by the addition of 35-nm Ag nanoparticles. The same principle was applied to a 0.3-μm thick of Poly(TMSP)-based PSP and the advantage of nanoparticle addition was evaluated in a shock tunnel. It was confirmed that the SNR could be enhanced 1.6-fold using LSPR excitation. Copyright © 2008 by Yusuke Miura.
Experimental study on interference flow of a supersonic busemann biplane using pressure-sensitive paint technique

Hiroki Nagai, Soshi Oyama, Toshiyuki Ogawa, Naoshi Kuratani, Keisuke Asai

ICAS Secretariat - 26th Congress of International Council of the Aeronautical Sciences 2008, ICAS 2008　2008/12

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Using Pressure Sensitive Paint, the pressure distributions on thin wings of the Busemann biplane model were measured in the small supersonic indraft wind tunnel. The observed phenomenon is so complicated that it is completely different from the prediction of the simple two-dimensional theory. Referring to Schlieren photograph and CFD analysis, it is found that these complex pressure fields are caused by the shock wave generated downstream just behind the wing ridge line. The results of this experiment show that the interference between Busemann biplane wings is sensitive to a small change in flow condition. A care must be taken in a wind tunnel test to realize the design condition of Busemann biplane where the shock waves are completely cancelled with each other.
Surface pressure and flow field behind an oscillating fence submerged in turbulent boundary layer

Manjinder S. Saini, Jonathan, W. Naughton, Taro Yamashita, Hiroki Nagai, Keisuke Asai

4th AIAA Flow Control Conference　2008/12/01

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Multiple flow diagnostic techniques have been used for better understanding of a complex unsteady flow. In particular, phase-locked PSP and PIV measurements have been used to study the evolution of three-dimensional disturbances produced by an oscillating fence actuator that is immersed in a zero pressure gradient turbulent boundary layer. Finite fence effects, introduced due to reducing aspect ratio of the fence during its oscillations, appear to be the reason for the strong three dimensionality and non-uniform growth of the structure across the span. Strong suction pressures are observed on the surface due to an intense vortex closer to the edge of the fence. At the midspan, the structure grows rapidly and weakens, limiting the magnitude of low pressure region. Additionally, strong suction pressures were observed when the vortex stays closer to the plate surface, which occurs for a longer time period near the side edge of the fence. The use of multiple diagnostics provided a link between flow field and surface pressure footprints, yielding an understanding of the flow that would have not been possible with any one technique. Copyright © 2008 by Jonathan W. Naughton.
Experimental study on three-dimensional shock interference flow of a supersonic Busemann Biplane

OYAMA, S, NAGAI, H, ASAI, K

KSAS/JSASS Joint Int'l Symposium on Aerospace Engineering 2008　2008/11
Flow-induced vibration of a High-speed Train Running in a Tunnel

KODERA, T, NAGAI, H, ASAI, K, TERASHIMA, O

KSAS/JSASS Joint Int'l Symposium on Aerospace Engineering 2008　2008/11
Visualization of the heat flux distribution on a blunt-nosed body with an aerospike in hypersonic flow

HA, S. NAGAI, H, ASAI, K, NAKAKITA, K, TSUBOI, N

KSAS/JSASS Joint Int'l Symposium on Aerospace Engineering 2008　2008/11
An experimental study of plasma actuator performance in martian atmospher

TAKAGAKI, M, NAGAI, H, ASAI, K

5th International Conference on Flow Dynamics　2008/11

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8-12
Design and construction of Mars Wind Tunnel for simulating atmospheric flight on Mars

ANYOJI, M, NAGAI, H, ASAI, K

5th International Conference on Flow Dynamics　2008/11

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8-27
PSP measurement of the leeward-side pressure distribution of a simplified car model in yaw

YORITA, D, NAGAI, H, ASAI, K

5th International Conference on Flow Dynamics　2008/11

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8-30
Luminescent Differential-Pressure Sensor Based on Gas Transfer through Porous Membrane

YORITA, D, NAGAI, H, ASAI, K

13th International Symposium on Flow Visualization　2008/07

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ISFV13 (126)
Pressure-Sensitive Paint Measurement of Unsteady Pressure Field behind an Oscillating Fence Actuator

YAMASHITA, T, NAGAI, H, ASAI, K, SINGH, M. AND, NAUGHTON, J. W

13th International Symposium on Flow Visualization　2008/07

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ISFV13 (130)
Visualization of Interacting Flow Field between Busemann's Biplane in Supersonic Flow

KURATANI, N, NAGAI, H, ASAI, K, OGAWA, T, OBAYASHI, S

13th International Symposium on Flow Visualization　2008/07

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ISFV13 (301)
Experimental Study on Interference Flow of a Supersonic Busemann Biplane using Pressure-Sensitive Paint Technique

NAGAI, H, OYAMA, S, OGAWA, T, KURATANI, N, ASAI, K

International Council of the Aeronautical Sciences 2008　2008/07

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ICAS2008-3.7.5
PSP Measurement of the Leeward-Side Pressure Distribution of a Simplified Car Model in Yaw

YORITA Daisuke, NAGAI Hiroki, ASAI Keisuke, TANAKA Shingo, ISHIDA Keitaro

Journal of the Visualization Society of Japan　2008/07/01
Surface Pressure and Flow Field Behind an Oscillating Fence Submerged in Turbulent Boundary Layer

SINGH, M, NAUGHTON, J. W, YAMASHITA, T, NAGAI, H, ASAI, K

26th AIAA Aerodynamic Measurement Technology and Ground Testing Conference　2008/06

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AIAA 2008-4073
Evaluation of Plasma Actuator Performance in Martian Atmosphere for Applications to Mars Airplane

TAKAGAKI, M, ISONO, S, NAGAI, H, ASAI, K

38th Fluid Dynamics Conference　2008/06

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AIAA-2008-3762
Thermal performance of a Miniature Loop Heat Pipe for Spacecraft Thermal Control System

Nagai Hiroki, Nagano Hosei, Fukuyoshi Fuyuko, Ogawa Hiroyuki

Proceedings of National Heat Transfer Symposium　2008

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近年、惑星探査や月面着陸などミッションの高度化に伴い、より高性能で複雑な熱制御技術が必要とされている。特に、熱環境が複雑に変動するミッションにおいて、衛星の熱設計を高温側および低温側で同時に満足できるような熱制御技術が重要である。そこで、アメリカをはじめ海外では次世代のスタンダードな熱制御技術として毛細管駆動型二相流体ループ（ループヒートパイプ：LHP）が開発されてきた。本研究では日本の将来の宇宙ミッションを見据え、100W級の小型LHPに着目し、その起動特性ならびに熱輸送特性の評価を行った。
Evaluation of lifetime-based pressure-sensitive paint measurement in low-speed flow

Taro Yamashita, Hiroki Nagai, Keisuke Asai

ICIASF Record, International Congress on Instrumentation in Aerospace Simulation Facilities　2007/12/01

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The lifetime-based method has been applied to Pressure-Sensitive Paint (PSP) measurement in low-speed flow. Based on theoretical considerations and sample tests, a method to calculate pressure using "a-priori" method was proposed. In this method, pressure is related to the ratio of the luminescent intensity ratios obtained at two different gates between the windon and wind-off conditions, multiplied by a temperature correction factor calculated from the single-point measurement of model substrate temperature. The sample tests showed that the effect of temperature as well as non-uniformity of lifetime could be cancelled out by the proposed method. In order to evaluate the effectiveness of this method, a simplified car model was tested in a low-speed wind tunnel. The result obtained by the lifetime method was in good agreement with those of pressure taps and the intensity method. © 2007 IEEE.
Development of pressure-sensitive paint technique in a supersonic indraft wind tunnel and its application to a busemann biplane

K. Saito, H. Nagai, T. Ogawa, K. Asai

ICIASF Record, International Congress on Instrumentation in Aerospace Simulation Facilities　2007/12/01

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Using Pressure Sensitive Paint, the pressure distributions on thin wings of the Busemann biplane model were measured in the small supersonic indraft wind tunnel. The observed phenomenon is so complicated that it is completely different from the prediction of the simple 2-D theory. Referring to Schlieren picture and CFD analysis, it is found that these complex pressure fields are caused by the shock wave generated downstream just behind the wing ridge line. The results of this experiment show that the interference between Busemann biplane wings is sensitive to a small change in flow condition. A care must be taken in a wind tunnel test to realize the design condition of Busemann biplane where the shock waves are completely cancelled with each other. © 2007 IEEE.
Thermal performance of a miniature loop heat pipe for spacecraft thermal control system

Hiroki Nagai, Hosei Nagano, Fuyuko Fukuyoshi, Hiroyuki Ogawa

2007 Proceedings of the ASME/JSME Thermal Engineering Summer Heat Transfer Conference - HT 2007　2007/12

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The Loop Heat Pipes (LHPs) are robust, self-starting and a passive two-phase thermal control system that uses the latent heat of vaporization of an internal working fluid to transfer heat from an evaporator (the heat source) to a condenser (the heat sink). The circulation of the working fluid is accomplished by capillary pressure gradients in a fine porous wick with very small pores. LHPs are rapidly gaining acceptance in the aerospace community and several terrestrial applications are emerging as well. In the present study, a miniature LHP is investigated the thermal performance for spacecraft thermal control system. Tests will be conducted including start-up, low power, power ramp up, high power, rapid power change, and rapid sink temperature change. Finally, we want to demonstrate the potential of LHP to become the next-generation heat transfer device to cool terrestrial devices such as advanced electronic which have high power dissipations. First of all, this paper presents the influence of the gravitational forces on the LHP performance. The present tests performed under steady state condition with three different orientations (horizontal, gravity-assisted, anti-gravity). Copyright © 2007 by ASME.
Measurement of oxygen partial pressure distribution in a fuel cell using pressure-sensitive paint

Suguru Inagaki, Hiroki Nagai, Keisuke Asai

2007 Proceedings of the ASME/JSME Thermal Engineering Summer Heat Transfer Conference - HT 2007　2007/12

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To improve efficiency and service life of a fuel cell, it is important to understand the dynamic behavior of oxygen molecules in the cell. In other words, we need to know the oxygen concentration distribution over electrode planes and inside diffused layers in addition to its time variation. We applied the Pressure-Sensitive Paint (PSP) technique to this problem, attempting to measure distribution of partial pressure oxygen along micro channels of a fuel cell. To prevent the effect of water produced by the power generation process, we developed a water-repellent PSP that can withstand heat and humidity produced by power generation. Using this paint, partial oxygen distribution along the micro channels was successfully visualized, although there were noticeable effects of local temperature distribution on the absolute accuracy for the conditions with higher current densities. Copyright © 2007 by ASME.
F231 Study on a Small Loop Heat Pipe : Improvement of Loop Operating Characteristics with Active Temperature Control of a Reservoir

Nagano Hosei, Fukuyoshi Fuyuko, Ogawa Hiroyuki, Nagai Hiroki

Procee[d]ings of Thermal Engineering Conference　2007/11/23

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This paper presents an experimental study to investigate the effectiveness of using a thermoelectric converter to control the loop heat pipe operating temperature. The compensation chamber (CC) was controlled at the set point temperature by cooling and heating the TEC module, of which one side is attached to the CC and the other side is connected to the evaporator through a thermal strap. The test results show that the TEC can control the operating temperature to the set point temperature. The power saving by using the TEC was also demonstrated.
Visualization of hypersonic compression corner flows using temperature- And pressure-sensitive paints

Y. Ishiguro, Y. Ishiguro, H. Nagai, H. Nagai, K. Asai, K. Asai, K. Nakakita, K. Nakakita

Collection of Technical Papers - 45th AIAA Aerospace Sciences Meeting　2007/07/02

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When a winged reentry vehicle like the Space Shuttle reenters the atmosphere, its external surfaces are exposed to intense aerodynamic heating. This is one of the most critical problems of designing the reentry vehicle. In this study, we investigated aerodynamic heating phenomena on a compression corner model that simulated a body flap of a reentry vehicle exposed in hypersonic airflow. The tests were conducted at Mach 10 in the JAXA 0.44-m Hypersonic Shock Tunnel and heat flux caused by aerodynamic heating on the model surface was measured by using Temperature-Sensitive Paint (TSP), which is a global temperature measurement technique based on photochemical reaction. In the present study, we succeeded in getting quantitatively heat flux distribution mages caused by aerodynamic heating of the hypersonic flow. It is found that the heat flux distribution on the model are caused by shock/shock and shock/boundary layer interaction, and the magnitude of the heat flux changes significantly depending on types of shock interactions for various angles of attack.
Unsteady flow measurements of a slender delta wing in wing rock motion

Yuichi Hirose, Yuichi Hirose, Hiroki Nagai, Hiroki Nagai, Keisuke Asai, Keisuke Asai

Collection of Technical Papers - 45th AIAA Aerospace Sciences Meeting　2007/07/02

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A delta wing sets up self-excited rolling oscillation known as "wing rock" when it is placed in flow at high angles of attack. In this study, wind-tunnel tests of a slender-delta wing with 80-deg sweep angle at subsonic speeds were conducted. The phase-lock technique with a fast-responding Pressure-Sensitive Paint (PSP) has been employed to visualize unsteady pressure distribution on the oscillating model during the entire wing-rock cycle. Analysis of the PSP results together with roll angle measurement and high-speed Schlieren images has revealed that the lag in the leading-edge vortex displacement and the delay of vortex breakdown play an important role in rocking motion of the delta wing. In the present experiment, PSP has proved to be a powerful tool to study the interaction of vortices with a model in rocking motion. This technique will be used to analyze the driving mechanism of the wing rock and its controlin details.
Measurement of Oxygen Partial Pressure Distribution in Fuel Cell using Pressure-Sensitive Paint

Inagaki, S, Nagai, H, Asai, K

2007 ASME-JSME Thermal Engineering Summer Heat Transfer Conference　2007/07

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HT2007-32751
Thermal Performance of a Miniature Loop Heat Pipe for spacecraft thermal control system

Nagai, H, Nagano, H, Fukuyoshi, F, Ogawa, H

2007 ASME-JSME Thermal Engineering Summer Heat Transfer Conference　2007/07

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HT2007-32805
Development of luminescent differential-pressure sensor based on porous membrane

YORITA Daisuke, NAGAI Hiroki, ASAI Keisuke

可視化情報学会誌 = Journal of the Visualization Society of Japan　2007/07/01
Evaluation of Lifetime-based Pressure-Sensitive Paint Measurement in Low-speed Flow

YAMASHITA Taro, NAGAI Hiroki, ASAI Keisuke

可視化情報学会誌 = Journal of the Visualization Society of Japan　2007/07/01
Pressure-Sensitive Paint Measurement of Flow around High-Speed Trains with Different Tail Shapes

KODERA Takeyuki, YAMASHITA Taro, ASAI Keisuke, NAGAI Hiroki, MORITA Kiyoshi

Journal of the Visualization Society of Japan　2007/07/01
Development of Pressure-Sensitive Paint Technique in a Supersonic Blowdown Wind Tunnel and its Application to a Busemann Biplane

Saito, K, Ogawa, T, Nagai, H, Asai, K

22nd International Congress on Instrumentation in Aerospace Simulation Facilities　2007/06
Evaluation of Lifetime-based Pressure-Sensitive Paint Measurement in Low-speed Flow

Yamashita, T, Nagai, H, Asai, K

22nd International Congress on Instrumentation in Aerospace Simulation Facilities　2007/06
Unsteady Flow Measurements of a Slender Delta Wing in Wing Rock Motion

HIROSE, Y, NAGAI, H, KURASHINA, D, ASAI, K

45th AIAA Aerospace Science Meeting and Exhibit　2007/01

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AIAA paper 2007-124
Visualization of Hypersonic Compression Corner Flows Using Temperature- and Pressure- Sensitive Paints

ISHIGURO, Y, OHMI, S, NAGAI, H, ASAI, K, NAKAKITA, K

45th AIAA Aerospace Science Meeting and Exhibit　2007/01

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AIAA paper 2007-118
Development of luminescent differential-pressure sensor based on porous membrane

YORITA Daisuke, NAGAI Hiroki, ASAI Keisuke

Transactions of Visualization Society of Japan　2007

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Pressure-Sensitive Paint (PSP) is applied to various wind tunnel tests as a useful technique to measure pressure distribution on model surfaces. PSP is inherently an absolute pressure sensor so that it is difficult to use this technique in low-speed flow where pressure change on a model is very small. To measure pressure with a high degree of accuracy at low speeds, we have developed a new type of PSP that responds to differential pressure rather than absolute pressure. This novel technique uses porous membrane through which gas containing no oxygen (e.g. nitrogen) is transported from the backside to the front side by pressure difference between the two. The transported gas purges oxygen near the surface and luminescence of PSP is enhanced. The results of sample tests show that the pressure sensitivity of the new PSP is higher than that of the current PSP by a factor of 100 times or more. In addition, the response of this sensor to differential pressure is almost linear and highly reproducible.
Pressure-Sensitive Paint Measurement of Flow around High-Speed Trains with Different Tail Shapes

KODERA Takeyuki, YAMASHITA Taro, ASAI Keisuke, NAGAI Hiroki, MORITA Kiyoshi

Transactions of Visualization Society of Japan　2007

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Optimizing the performance and increasing the comfort of high-speed trains require the knowledge of aerodynamic effects of a train shape. One of the most critical problems is a compression wave caused by a train entering a tunnel. This noise mainly depends on the cross-sectional area distribution of a train nose. On the other hand, the aerodynamic drag, the stability for side wind, and the low-frequency vibration are attributed to tail shapes. In this study, we studied the effects of train tail shapes on the flow field experimentally. Two models having the same cross-sectional area distribution but with different tail shapes were tested in a low-speed wind tunnel. To analysis the flow field around the model, we used pressure sensitive paint and oil flow techniques. As a result, we could identify the effects of tail shapes for pressure drag and cross wind stability.
Application of lifetime PSP imaging method to a cryogenic wind tunnel

Toshiyuki Kojima, Toshiyuki Kojima, Hiroki Nagai, Hiroki Nagai, Keisuke Asai, Keisuke Asai, Kazunori Mitsuo, Yoshimi Iijima, Hirotaka Sakaue, Hirotaka Sakaue

Collection of Technical Papers - 44th AIAA Aerospace Sciences Meeting　2006/12/01

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The intensity-based method is a most common technique to convert Pressure-Sensitive Paint (PSP) images to surface pressure. However, this method is not suitable for a cryogenic wind tunnel because the thermal equilibrium condition cannot be achieved when the tunnel is stopped to take the wind-off reference image. In the present study, we applied the lifetimebased PSP imaging method to a cryogenic wind tunnel. Using this method, surface pressure can be calculated from two images obtained at the wind-on condition. In this experiment, a circular-arc bump model coated with PtTFPP/PTMSP paint was tested in the JAXA 0.1-m Cryogenic Transonic Wind Tunnel and PSP images were acquired using a UV-LED pulse illuminator and a multi-gated CCD camera. As a result, we succeeded in visualizing surface pressure distribution induced by a shock wave on the model by using lifetime imaging technique. However, nonnegligible deviation from pressure tap data was observed for the lifetime-based PSP data in the region of the model leading- and trailing- edges. Also the lifetime-based PSP data showed relatively rapid deterioration. These anomalies were not observed in the intensity-based PSP data in the same experiment. To use lifetime PSP imaging method for quantitative pressure measurement, photo-physical mechanism behind these anomalies should be clarified.
PSP measurement of pressure distribution in a supersonic micronozzle

H. Nagai, H. Nagai, R. Naraoka, R. Naraoka, K. Sawada, K. Sawada, K. Asai, K. Asai

Collection of Technical Papers - 44th AIAA Aerospace Sciences Meeting　2006/12/01

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In recent years, an interest in micro devices and systems has increased rapidly, and this trend is expected to continue for years to come. Gaseous flow through and within such devices is a principal consideration in many applications, and its understanding can be crucial for optimization of performance. Detailed understanding of fundamental physical processes on these small scales is hampered by the lack of suitable quantitative measurement tools (pressure and temperature sensors, etc.). Pressure-sensitive paint (PSP) is one of the options for global distribution measurement in MEMS devices. PSP is a "molecular sensor," and has an enough resolution for MEMS. In this paper, we demonstrate the use of PSP for quantitative measurement of pressure distribution in supersonic micronozzles of the nozzle throat 250μm, such as those that might be employed for flow control and/or small satellite orbit maintenance. And we compare the experimental result with numerical simulation by the conventional Reynolds-averaged Navier-Stokes equations in the three-dimensional space.
Effect of TSP layer thickness on global heat transfer measurement in hypersonic flow

Shunsuke Ohmi, Shunsuke Ohmi, Hiroki Nagai, Hiroki Nagai, Keisuke Asai, Keisuke Asai, Kazuyuki Nakakita, Kazuyuki Nakakita

Collection of Technical Papers - 44th AIAA Aerospace Sciences Meeting　2006/12/01

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Heat flux measurement in a hypersonic wind tunnel is one of indispensable requirements for designing the next generation re-entry vehicle. Heat flux is usually calculated from a temporal change in temperature on the model surface. Temperature-Sensitive Paint (TSP) is a global temperature measurement technique based on photochemical reaction. This technique was applied to a hypersonic shock tunnel, but there existed uncertainties caused by TSP layer thickness. In this study, the relationship between TSP layer thickness and measurement accuracy in heat flux was studied by experiment. TSP composed of Ru(phen) 3 2+ as luminophore and polyacrylic acid as binder was applied on a cylinder model made of glass ceramics. The thickness of TSP layer was varied from 0.2 to 3 μm. The models were tested at Mach 10 in the JAXA 0.44-m Hypersonic Shock Tunnel and heat flux caused by aerodynamic heating on the model surface was measured. A comparison between TSP data and conventional thermocouple data showed that the measurement error changed with the layer thickness In nonlinear fashion. In addition, the difference between TSP and thermocouple measurement was larger than theoretical prediction. For TSP layer thickness less than 0.5μm, the accuracy in heat flux measurement by TSP was within the uncertainty of conventional thin thermocouple measurement. To demonstrate the capability of TSP with the optimized thickness, tests using a 3-dimensional wing-body model have been conducted and the complicated heat flux pattern caused by shock-wave/shock-wave interaction has been observed.
Molecular Sensors in Microturbine Measurement

HUANG, C.Y, Gregory, J. W, NAGAI, H, ASAI,K, Sullivan, J. P

Proceedings of 2006 ASME International Mechanical Engineering Congress and Exposition　2006/11

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IMECE2006-13814
G303 Flow Field Measurement of a Simplified Car Model using Pressure-Sensitive Paint(2)

SUGIURA Hikaru, YAMASHITA Taro, NAGAI Hiroki, ASAI Keisuke, ISHIDA Keitaro

Fluids engineering conference ...　2006/10/28

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Yawing moment and side force affect behavior of an automobile in crosswind. In wind tunnel testing, these aerodynamic forces are usually measured using a strain-gage balance. However, using Pressure-Sensitive Paint (PSP), we can measure surface pressure and obtain the force acting on each surface. In the present study, pressure distribution on top and four side surfaces of a simplified car model (1/10 scale Ahmed model) was measured using PSP at yaw angle ψ= 0 and 20[deg]. As a result, we could correlate the negative pressure regions appeared in the PSP images with separated regions and vortices shown in oil flow. In the case of ψ= 20[deg], it was shown that pressure difference between the leeward side and the windward side produced unstable yawing moment.
G303 Flow Field Measurement of a Simplified Car Model using Pressure-Sensitive Paint(1)

SUGIURA Hikaru, YAMASHITA Taro, NAGAI Hiroki, ASAI Keisuke, ISHIDA Keitaro

Fluids engineering conference ...　2006/10/28
G302 Measurement of oxygen partial pressure distribution in a fuel cell using Pressure-Sensitive Paint(2)

Inagaki Suguru, Nagai Hiroki, Asai Keisuke

Fluids engineering conference ...　2006/10/28

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To improve efficiency and service life of a fuel cell, it is important to understand dynamic behavior of oxygen molecules in the cell. In other words, we need to know oxygen concentration distribution over electrode planes and inside diffused layers and its time variation. We applied Pressure-Sensitive Paint technique to this problem, attempting to measure distribution of partial pressure of oxygen along micro channels of a fuel cell. To prevent the effect of water produced by power generation process, we developed a water-repellant PSP that can withstand heat and humidity produced by power generation. Using this paint, partial oxygen distributions along the micro channels were successfully visualized, although there were noticeable effects of local temperature distribution on the absolute accuracy for the conditions with higher current densities.
G302 Measurement of oxyecoia pressure distribution in a fuel cell using pressure sensitive paint(1)

Inagaki Suguru, Nagai Hiroki, Asai Keisuke

Fluids engineering conference ...　2006/10/28
Application of Luminophore-Pendant Pressure-Sensitive Paint to Fluid Dynamic Measurements

SAKAUE, H, MITSUO, K, IIJIMA, Y, MORITA, K, HYAKUTAKE, T, TAGUCHI, H, NISHIDE, H, KOJIMA, T, NAGAI, H, ASAI, K

Proceedings of 12th International Symposium on Flow Visualization　2006/09

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ISFV12-60.1(234)
PSP Measurement of the Flow around a Simplified Car Model

Yamashita,T, Sugiura, H, Nagai, H, Asai, K, Ishida, K

Proceedings of 12th International Symposium on Flow Visualization　2006/09

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ISFV12-67.4(259)
Flow Diagnostic using PSP and TSP technique in a Supersonic Micronozzle

NAGAI, H, NARAOKA, R, SAWADA, K, ASAI, K

Proceedings of 12th International Symposium on Flow Visualization　2006/09

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ISFV12-33.2(244)
Effect of Temperature-Sensitive Paint Layer on Global Heat Transfer Measurement in Hypersonic Flow

NAGAI Hiroki, OHMI Shunsuke, ASAI Keisuke, NAKAKITA Kazuyuki

Journal of the Visualization Society of Japan　2006/07/01
PSP Measurement of the Flow around a Simplified Car Model

YAMASHITA Taro, SUGIURA Hikaru, NAGAI Hiroki, ASAI Keisuke, ISHIDA Keitaro

Journal of the Visualization Society of Japan　2006/07/01
Cryogenic Infrared Mission “JAXA/SPICA” with Advanced Cryocoolers

H.Sugita, T. Nakagawa, H. Murakami, A. Okamoto, H. Nagai, M. Murakami, K. Narasaki, M. Hirabayashi, SPICA Working Group

Cryogenics　2006
PSP measurement of Pressure Distribution in a Supersonic Micronozzle

NAGAI, H, NARAOKA, R, SAWADA, K, ASAI, K

44th AIAA Aerospace Science Meeting and Exhibit　2006/01

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AIAA paper 2006-1046
Application of Lifetime Imaging Method to a Cryogenic Wind Tunnel

KOJIMA, T, NAGAI, H, ASAI, K, MITSUO, K, IIJIMA, Y, SAKAUE, H

44th AIAA Aerospace Science Meeting and Exhibit　2006/01

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AIAA paper 2006-1044
Effect of TSP Layer Thickness on Global Heat Transfer Measurement in Hypersonic Flow

OHMI, S, NAGAI, H, ASAI, K, NAKAKITA, K

44th AIAA Aerospace Science Meeting and Exhibit　2006/01

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AIAA paper 2006-1048
Effect of Temperature-Sensitive Paint Layer on Global Heat Transfer Measurement in Hypersonic Flow

NAGAI Hiroki, OHMI Shunsuke, ASAI Keisuke, NAKAKITA Kazuyuki

Transactions of Visualization Society of Japan　2006

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Heat flux measurement in a hypersonic wind tunnel is one of indispensable requirements for designing the next generation re-entry vehicle. Heat flux is usually calculated from a temporal change in temperature on the model surface. Temperature-Sensitive Paint (TSP) is a global temperature measurement technique based on photochemical reaction. This technique was applied to a hypersonic shock tunnel test, but there existed uncertainties caused by TSP layer thickness. In this study, the relationship between TSP layer thickness and measurement accuracy in heat flux was investigated by experiment. The models were tested at Mach 10 in the JAXA 0.44-m Hypersonic Shock Tunnel and heat flux caused by aerodynamic heating on the model surface was measured. A comparison between TSP data and conventional thermocouple data showed that the measurement error changed with the layer thickness in nonlinear fashion. To demonstrate the capability of TSP with the optimized thickness, tests using a 3-dimensional wing-body model have been conducted and the complicated heat flux pattern caused by shock-wave/shock-wave interaction has been observed.
Molecular sensors in microturbine measurement

Chihyung Huang, James W. Gregory, Hiroki Nagai, Keisuke Asai, John, P. Sullivan

American Society of Mechanical Engineers, Micro-Electro Mechanical Systems Division, (Publications) MEMS　2006/01/01

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Microturbines have been studied for use in micro size engines as a fuel cell for power generation. These micro engines are designed to offer power output around a couple watts with a very small, compact size. However, there are a lot of difficulties for these small size turbines such as high friction, unstable rotor movement etc, that make the microturbines break down much earlier in their life cycle. These problems needed to be solved in order to improve the efficiency of microturbines. However, it is difficult to install micro sensors in the microturbine device for measurement. A novel technique of molecular sensor, known as pressure-sensitive paint and temperature-sensitive paint (PSP/TSP) has been developed to obtain the pressure and temperature field inside the microturbine device. The PSP sensors used in the experiments are PtTFPP/PolyTMSP for time-averaged pressure measurement, and PtTFPP/TMSP for phase-averaged pressure measurement. The TSP sensor of Ru(phen)3+/Polyacrylic is used for the temperature measurement. The PSP/TSP sensor is coated on glass slides and the glass slide is used as cover glass for the microturbine device. Pressure and temperature distributions inside the microturbine device have been successfully obtained with PSP and TSP sensors. The rotation speed for the microturbine varies from 1300 to 4000 rpm for different flow rates from 5 to 15 L/min for the time-averaged experiments. Phase-averaged results have been obtained with a laser triggering system at a rotation speed of 1400 rpm and volume flow rate of 17 L/min. The temperature map inside the microturbine has been acquired with the TSP sensor with a rotation speed from 1300 to 4000 rpm and flow rates from 5 to 15 L/min. The PSP/TSP sensor has been demonstrated with the feasibility of measuring the pressure and temperature field inside the microturbine device with high spatial resolution, both in time-averaged and phase-averaged measurements. Copyright © 2006 by ASME.
Performance evaluation of double-condenser loop heat pipe onboard monitor of all-sky x-ray image (MAXI) in thermal vacuum testing

Hiroki Nagai, Shiro Ueno

SAE Technical Papers　2005/12

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The thermal performance of the Loop Heat Pipe Radiator System (LHPRS) has been verified in the thermal vacuum testing. LHPRS is used as the heat transport system to reject heat from the Monitor of All-sky X-ray Image (MAXI). Since this LHPRS was designed exclusively for the MAXI system, it has two-condensers in parallel connected to a common evaporator. Since it is possible that the heat transportation deviates to one condenser only, it had to be investigated how the double condensers affect the LHPRS performance under various conditions. Thermal vacuum testing was conducted for the engineering model of the MAXI/LHPRS. In this paper, the test result and performance verification of the MAXI/LHPRS are described. Copyright © 2005 SAE International.
Innovative cryogenic system for Japanese infrared astronomical mission "spica"

Hiroyuki Sugita, Takao Nakagawa, Hiroshi Murakami, Toshio Matsumoto, Hiroki Nagai, Masahide Murakami, Katsuhiro Narasaki, Masayuki Hirabayashi

International Astronautical Federation - 56th International Astronautical Congress 2005　2005/12

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Since the next cryogenic infrared mission "JAXA-SPICA" employs advanced mechanical cryocoolers with effective radiant cooling in place of cryogen, the primary mirror, 3.5 m in diameter, and the optical bench can be maintained at 4.5 K for at least 5 years. First, the feasibility of the thermal design of the cryogenic system is presented. A 20K-class Stirling cryocooler was then improved in cooling capacity and reliability for the mission, and the effects of contaminated working gas or new regenerator materials on cooling performance were investigated. Development of a new 3 He-JT (Joule-Thomson) cryocooler for use at 1.7 K is also described, along with the successful results of a cooling capacity higher than the required 10 mW. A 4K-class cryocooler was modified and developed for higher reliability over a five-year operational life and a higher cooling capacity exceeding the current 30 mW. Finally, we discuss a system for heat rejection from cryocoolers using thermal control devices.
Thermal performance verification for the JEM MAXI loop heat pipe and radiator system

Hiroki Nagai, Shiro Ueno

International Astronautical Federation - 56th International Astronautical Congress 2005　2005/12/01

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The thermal performance of the Loop Heat Pipe and Radiator System (LHPRS) has been verified in the thermal vacuum testing. LHPRS is used as the heat transport system to reject heat from the Monitor of All-sky X-ray Image (MAXI). Since this LHPRS was designed exclusively for the MAXI system, it has two-condensers in parallel connected to a common evaporator. Since it is possible that the heat transportation deviates to one condenser only, it had to be investigated how the double condensers affect the LHPRS performance under various conditions. Thermal vacuum testing was conducted for the engineering model of the MAXI/LHPRS. In this paper, the test result and performance verification of the MAXI/LHPRS are described.
Start-up behavior of double-condenser loop heat pipe

H. Nagai, M. Muto, M. Murakami, S. Ueno

38th AIAA Thermophysics Conference　2005/12/01

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A loop heat pipe (LHP) is used as the heat transport device to reject heat from the Monitor of All-sky X-ray Image (MAXI) [1]. Since this LHP was designed exclusively for the MAXI system, it is different from conventional LHPs [2-4] in the configuration that it has two-condensers connected in parallel to a common evaporator. Each of the radiators has different radiation area and thus the different pipe length of the condenser. It is anticipated that the thermal condition of each condenser may be independent of each other because they point toward different directions. We experimentally investigated the effects of the particular design of this LHP on the heat transfer performance on the ground. Especially, we focus on the start-up behavior from a low power state that might be one of the technical concerns for the LHP. © 2005 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
Thermal performance verification for the JEM MAXI Loop Heat Pipe and Radiator System

Hiroki Nagai, Shiro Ueno

Proceedings of 56th International Astronautical Congress　2005/10

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IAC-05-B4.3.08
Innovative Cryogenic System for Japanese Infrared Astronomical Mission “SPICA”

H. Sugita, T. Nakagawa, H. Murakami, T Matsumoto, H. Nagai, M. Murakami, K. Narasaki, M. Hirabayashi

Proceedings of 56th International Astronautical Congress　2005/10

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IAC-05-A3
Performance Evaluation of Double-condenser Loop Heat Pipe onboard Monitor of All-sky X-ray Image (MAXI) in Thermal Vacuum Testing

Hiroki Nagai, Shiro Ueno

Proceedings of the 35th International Conference on Environmental　2005/07

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05ICES-153
Start-up Behavior of Double-condenser Loop Heat Pipe

NAGAI, H, MUTO, M, MURAKAMI, M, UENO, S

Proceedings of 38th AIAA Thermophysics Conference　2005/06

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AIAA 2005-4956
Self-induced Temperature Oscillation of Double Condenser Design Loop Heat Pipe

NAGAI, H, MUTO, M, MURAKAMI, M, UENO, S

Proceedings of the 6th World Conference on Experimental Heat Transfer, Fluid Mechanics and Thermophysics 2005　2005/04

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7-b-5
Effect of TSP Layer Thickness on Global Heat Transfer Measurement in a Hypersonic Shock Tunnel

OHMI Shunsuke, NAGAI Hiroki, ASAI Keisuke, NAKAKITA Kazuyuki

Journal of the Visualization Society of Japan　2005/03/15
Application of Lifetime PSP Imaging Method to a Cryogenic Wind Tunnel

KOJIMA Toshiyuki, NAGAI Hiroki, ASAI Keisuke, MITSUO Kazunori, IIJIMA Yoshimi, SAKAUE Hirotaka

Transactions of Visualization Society of Japan　2005/03/15

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The intensity-based method is a most common technique by which Pressure-Sensitive Paint images can be converted to the surface pressure. However, this method cannot be applied to a cryogenic wind tunnel because the thermal equilibrium condition cannot be achieved when stopping the tunnel to take the wind-off reference image. In the present experiment, we applied the lifetime-based method to a cryogenic wind tunnel to calculate surface pressure from two images obtained during the wind-on condition. In this experiment, the circular-arc bump model sprayed with PtTFPP/PTMSP paint was tested at the JAXA 0.1m Cryogenic Transonic Wind Tunnel using a UV-LED pulse illuminator and a multi-gated CCD camera. As a result, we could succeed in visualizing surface pressure distribution induced by a shock wave on the model by using lifetime PSP imaging method. This result has demonstrated a feasibility of using lifetime imaging method to a cryogenic wind tunnel.
PSP measurement of Pressure Distribution in a Supersonic Micronozzle

NAGAI Hiroki, NARAOKA Ryota, ASAI Keisuke

可視化情報学会誌. Suppl.　2005/03/15
新世代ヒートパイプLoop Heat Pipe

上野史郎, 永井大樹

宇宙科学シンポジウム　2005/01/06
Effect of TSP Layer Thickness on Global Heat Transfer Measurement in a Hypersonic Shock Tunnel

Ohmi Shunsuke, Nagai Hiroki, Asai Keisuke, Nakakita Kazuyuki

Transactions of Visualization Society of Japan　2005

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Heat flux measurement in a wind tunnel is an indispensable requirement for the next generation re-entry vehicle design. Heat flux is usually calculated from a temporal change in surface temperature. Temperature-Sensitive Paint (TSP) is a global temperature measurement technique based on photochemical reaction. This technique has been already applied to a hypersonic shock tunnel, but poses some problems caused by TSP layer thickness. In this paper, the relationship between TSP layer thickness and measurement accuracy in heat flux was studied systematically. A test model is made of engineering ceramic, which coated with TSP composed of Ru(phen)³⁺ as luminophore and polyacrylic acid as binder. The layer thickness was varied from 1 to 9 micro meters. Wind tunnel tests were conducted in the JAXA 0.44-m Hypersonic Shock Tunnel. The model was tested in Mach 10 hypersonic flow and heat flux caused by aerodynamic heating was measured. A comparison between TSP data and conventional thermocouple data showed that the relationship between the layer thickness and the temperature error is not a simple liner relationship predicted by the theory. The deviation from the theory is significant particularly for the cases with very thin coatings.
PSP measurement of Pressure Distribution in a Supersonic Micronozzle

NAGAI Hiroki, NARAOKA Ryota, ASAI Keisuke

Transactions of Visualization Society of Japan　2005

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In recent years, the interest in microdevices and systems has increased rapidly. Gaseous flow through and within such devices is a principal consideration in many applications, and its understanding can be crucial for optimization of performance. Most of the sensors applied to MEMS devices measurement have limited resolution restricted by the sensor size and device geometry. Pressure-sensitive paint (PSP) is one of the options for global distribution measurement in MEMS devices. PSP is a "molecular sensor, " and has an enough resolution for MEMS. In this paper, we demonstrate the use of PSP for quantitative measurement of pressure distribution in a supersonic micronozzle of the nozzle throat 250μm, such as those that might be employed for flow control and/or small satellite orbit maintenance.
Space cryogenic system for SPICA mission

Hiroyuki Sugita, Hiroki Nagai, Takao Nakagawa, Hiroshi Murakami, Toshio Matsumoto, Masahide Murakami, Katsuhiro Narasaki, Masayuki Hirabayashi

Proceedings of SPIE - The International Society for Optical Engineering　2004/12/20

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This paper describes that the feasibility of the next Japanese infrared astronomical SPICA mission is verified in thermal design by numerical analyses and developed technologies. In this advanced cryogenic mission, in order to cool the large primary mirror and focal plane instruments down to 4.5 K for 5 years or longer without cryogen, the mechanical cooling is employed with effective radiant cooling, which compensates the limited cooling capacity of the JT cryocooler for 4.5 K upgraded from that developed for the "JEM/SMILES" mission on the International Space Station. First, thermal design of the telescope is numerically discussed with thermal mathematical models. Some configurations of radiators, shields and solar-array paddles are investigated and compared in technical and mission feasibilities. Next, the development status of the 3 He-JT circuit with the Stirling cryocooler for one detector operated at the lowest temperature of 1.7 K is reported. The recent results of experiments give that the breadboard model of the 1.7 K cryocooler successfully exceeds the required cooling capacity of 10mW at 1.7K with small power consumption. Finally, the heat rejection system from those cryocoolers is discussed. As a promising candidate, the loop heat pipe is chosen and suitably designed.
Development of Porous Aluminum by Metal Injection Moulding

NISHIYABU, K, MATSUZAKI, S, ISHIDA, M, TANAKA, S, NAGAI, H

Proceedings of the 9th International Conference on Aluminum Alloys　2004/08
Space Cryogenic System for SPICA Mission

H. Sugita, H. Nagai, T. Nakagawa, H. Murakami, T. Matsumoto, M. Murakami, K. Narasaki, M. Hirabayashi

Astronomical Telescopes and Instrumentation　2004/06
JEM/MAXI冷却システム用ループヒートパイプの評価試験

永井大樹, 上野史郎, 松岡勝

宇宙科学シンポジウム　2004/01/08
次期赤外線天文衛星SPICAの冷却系開発

杉田寛之, 永井大樹, 中川貴雄

宇宙科学シンポジウム　2004/01/08
Steady and transient behavior of a double-condenser design LHP for MAXI

Hiroki Nagai, Miki Muto, Masahide Murakami, Shiro Ueno, Masaru Matsuoka

36th AIAA Thermophysics Conference　2003/12/01

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A loop heat pipe (LHP) is used as the heat transport device to reject heat from the Monitor of All-sky X-ray Image (MAXI). Since this LHP was designed exclusively for the MAXI system, it is different from conventional LHPs in configuration, a double-condenser design. We experimentally investigated the effects of the particular design of this LHP on the heat transfer performance by using the LHP Ground Test Unit (GTU) on the ground. The steady heating experiment was carried out to investigate the steady state performance of LHP. When the two condensers were cooled at different temperatures under a steady heating condition, a quasi-periodic temperature oscillation was observed in the evaporator and accumulator area. We experimentally investigated the cause and mechanism of the temperature oscillation.
Transient and Start-up Behavior of a Double-Condenser Design LHP for Monitor of All Sky X-ray Image (MAXI)

NAGAI, H, MUTO, M, MURAKAMI, M, UENO, S, MATSUOKA, M

Proceedings of the 7th International Heat Pipe Symposium　2003/10
Steady and Transient Behavior of a Double-Condenser Design LHP for MAXI

NAGAI, H, MUTO, M, MURAKAMI, M, UENO, S, MATSUOKA, M

Proceedings of 36th AIAA Thermophysics Conference　2003/06

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AIAA 2003-3770
The Experimental Study of Thermo-Fluid Dynamic Phenomena caused by Shock Waves in Liquid Helium

FUTAYA Yuka, YANAKA Kazuyoshi, NAGAI Hiroki, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　2003/05/21
全天X線監視装置(MAXI)搭載CCDカメラ冷却用ループヒートパイプ(LHP)の伝熱特性に関する地上実験

永井大樹, 上野史郎, 松岡勝

宇宙科学シンポジウム　2003/01/09
Thermal behavior of a double-condenser design LHP for Monitor of All-sky X-ray Image

Miki Muto, Masahide Murakami, Hiroki Nagai, Shiro Ueno, Masaru Matsuoka

SAE Technical Papers　2002/12

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A loop heat pipe (LHP) is used as the heat transport device to reject heat from the Monitor of All-sky X-ray Image (MAXI). Since this LHP was designed exclusively for the MAXI system, it is different from conventional LHPs in configuration, a double-condenser design. We experimentally investigated the effects of the particular design of this LHP on the heat transfer performance by using the LHP Ground Test Unit (GTU) on the ground. The steady heating experiment was carried out to investigate the effective thermal conductance through the comparison with the prediction. When the two condensers were cooled at different temperatures under a steady heating condition, a quasi-periodic temperature oscillation was observed in the evaporator and accumulator area. Copyright © 2002 Society of Automotive Engineers, Inc.
Thermal Behavior of a Double-Condenser Design LHP for Monitor of All-sky X-ray Image

MUTO, M, NAGAI, H, MURAKAMI, M, UENO, S, MATSUOKA, M

Proceedings of the 32th International Conference on Environmental　2002/07
Thermal Shock Wave in He II induced by Gasdynamic Shock Wave Impingement onto He II Free Surface

YANAKA, K, UETA, Y, MURAKAMI, M, YANG, H.S, NAGAI, H

Proceedings of 19th International Cryogenic Engineering Conference　2002/07
He II-to-He I λ-Phase Transition Induced by Shock Compression

YANAKA Kazuyoshi, UETA Yasuhiro, MURAKAMI Masahide, NAGAI Hiroki, YANG HyungSuk

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　2002/05/18
Experimental Study for shock wave propagation of He II with Lambda Phase Transition

NAGAI, H, UETA, Y, YANAKA, K, MURAKAMI, M

Proceedings of 19th International Cryogenic Engineering Conference　2002
Experiments of Highly Transient Thermo-fluid dynamic Phenomena in He II induced by Gas Dynamic Shock wave Impingement

NAGAI, H, MURAKAMI, M, YANG, H.S, UETA, Y, YANAKA, K

Advances in Cryogenic Engineering　2002
Thermal Analysis and Predictive Accuracy by using CAD System

永井大樹, 二俣亮介

Proceedings of the Annual Conference of the Japan Society for Industrial and Applied Mathematics　2002

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衛星の熱解析を行う際に、解析の対象物が大きくなったり複雑になったりすると、解析で用いる熱数学モデルの作成に多大な時間と労力が必要となる。従って、熱解析を効率よく、短時間に行うためにCADシステムを導入した解析手法が取られるようになっている。これにより、形状モデルの作成や変更に対して素早く対応することが可能となっている。本講演では、このCADシステムを利用した衛星熱設計手法と予測精度に関して、今年２月に打ち上げられたH2A２号機に搭載された実証衛星MDS-1を例として話をする。
Propagation of a compression shock wave in He II induced by gasdynamic shock wave impingement onto He II free surface

UETA, Y, NAGAI, H, YANG, H.S, MURAKAMI, M, YANAKA, K

Proceedings of the 23rd International Synposium on Shock Wave　2001/07
Experimental Study of Thermal Shock Wave in Superfluid Shock Tube Facility

NAGAI, H, MURAKAMI, M, YANG, H.S, UETA, Y, YANAKA, K

Proceedings of the 23rd International Symposium on Shock Wave　2001/07
Application of the superfluid shock tube facility to the study of ultra-high Reynolds number flow

YANAKA Kazuyoshi, YANG HyungSuk, UETA Yasuhiro, NAGAI Hiroki, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　2001/05/16
Experimental Study of Thermo-Fluid Dynamic Phenomena in Superfluid Helium by using Superfluid Shock Tube Facility

NAGAI, H, UETA, Y, YANG, H.S, Murakami, M, YANAKA, K

Proceedings of the 5th World Conference on Experimental Heat Transfer, Fluid Mechanics and Thermophysics 2001　2001
Propagation of a compression shock wave in He II induced by shock impingement

MURAKAMI Masahide, UETA Yasuhiro, YANAKA Kazuyoshi, NAGAI Hiroki, YANG Hung Suk

日本流体力学会年会講演論文集　2001

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The propagation of a compression shock wave in superfluid helium (He II) was experimentally investigated by using the superfluid shock tube facility. A shock wave is generated in He II by the impingement of a gas dynamic shock wave onto vapor-He II interface. In fact, upon the impingement two modes of shock waves, a compression and a thermal shock waves, are induced in He II. Here, we are only interested in the former. One of our research target is the shock-compressed phase transition (He II to He I). The λ-phase transition is successfully caused in such a very rapid process as shock wave compression. The shock wave propagation properties are measured by piezo-type pressure transducers and in-house-made superconductive temperature sensors. Schlieren visualization method is also adopted with an ultra-high-speed video recorder (40,500 pictures/s).
Generation and Development of The Thermal Boundary Layer near Shock-Compressed He II-Vapor Interface

UETA Yasuhiro, YANG HyungSuk, NAGAI Hiroki, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　2000/10/31
Experimental Study of He II-He I Lambda-transition induced by shock compression

NAGAI Hiroki, YANG HyungSuk, UETA Yasuhiro, SATOU Ryuuji, MURAKAMI Masahide, YANAKA Kazuyoshi

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　2000/10/31
Experimental Study on Shock Wave Phenomena in Superfluid Helium

NAGAI, H, MURAKAMI, M

Proceedings of the 3rd Asian-Pacific Conference on Aerospace Technology and Science　2000/10
Propagation of Thermal Shock Wave in Compressed He II induced by a Gasdynamic Shock Wave Impingement

YANG, H.S, NAGAI, H, MURAKAMI, M, UETA, Y

Proceedings of 18th International Cryogenic Engineering Conference　2000/02
Experimental Study of Shock Waves in Superfluid Helium induced by a Gasdynamic Shock Wave Impingement

YANG, H.S, NAGAI, H, MURAKAMI, M, UETA, Y

Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics　2000/02
Thermal Shock Wave induced by a Gasdynamic Shock Wave Impingement to He II Free Surface

YANG HyungSuk, NAGAI Hiroki, UETA Yasuhiro, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　1999/11/10
Study of two modes of shock waves and Lambda-transition in He II induced by shock compression

NAGAI, H, TAKANO, N, YANG, H.S, MURAKAMI, M

Proceedings of the 22nd International Symposium on Shock Waves　1999/07
Transient Phase Change of He II induced by Shock Compression

NAGAI Hiroki, TAKANO Nahoko, YANG HyungSuk, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　1999/06/07
Visualization Study of Phase Transitions of He II induced by Shock Wave Compression

TAKANO, N, NAGAI, H, YANG, H.S, MURAKAMI, M

Proceedings of 17th International Cryogenic Engineering Conference　1998/07
Investigation of Two Modes of Shock Wave in He II by Using Newly developed Superfluid Shock Tube Facility

NAGAI, H, YANG, H.S, TAKANO, N, MURAKAMI, M

Proceedings of 17th International Cryogenic Engineering Conference　1998/07
Temperature Variation caused by Shock Waves in He II

YANG HyungSuk, NAGAI Hiroki, TAKANO Nahoko, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　1998/05/20
Characteristics of propagating shock waves in He II

NAGAI Hiroki, YANG HyungSuk, TAKANO Nahoko, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　1998/05/20
Investigation of wave motion phenomena in superfluid helium by a gas dynamic shock wave incidence

YANG HyungSuk, NAGAI Hiroki, TAKANO Nahoko, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　1997/11/18
Development of Superfluid Shock Tube Facility

NAGAI Hiroki, YANG HyungSuk, TAKANO Nahoko, MURAKAMI Masahide

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　1997/11/18
超流動ヘリウム気液自由界面における第2音波の反射

古川徹, 村上正秀, 永井大樹

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　1996/11/06
Transient Evaporation Phenomena in a Pure Vapour-Liquid System

FURUKAWA, T, MURAKAMI, M, NAGAI, H, Iida, T

Proceedings of the 5th International Heat Pipe Symposium　1996/11
レーザーホログラフィー干渉計有限干渉縞法によるHe II中の熱流体現象の可視化

飯田光人, 村上正秀, 島崎毅, 永井大樹

低温工学・超電導学会講演概要集 = Meetings of Cryogenics and Superconductivity　1995/05/17
ikami

ikami

The 19th International Symposium on Flow Visualization

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Industrial Property Rights 12

変動画像解析方法および変動画像解析システム

依田大輔, 永井大樹, 浅井圭介

Property Type: Patent
変動画像解析方法および変動画像解析システム

依田大輔, 永井大樹, 浅井圭介

Property Type: Patent
光学的差圧計測手法および光学的差圧センサー

永井大樹, 浅井圭介

Property Type: Patent
光学的差圧計測手法および光学的差圧センサー

永井大樹, 浅井圭介

特許第5017512号

Property Type: Patent
ガス流可視化方法及び装置

箱崎譲優, 鎌田慎矢, 浅井圭介, 永井大樹

Property Type: Patent
酸素消光性塗料及び酸素濃度計測装置

箱崎譲優, 鎌田慎矢, 浅井圭介, 永井大樹

Property Type: Patent
酸素消光性塗料及び酸素濃度計測装置

箱崎譲優, 鎌田慎矢, 浅井圭介, 永井大樹

特許第4630991号

Property Type: Patent
燃料電池の酸素分圧分布等の計測方法とその装置等並びに燃料電池

箱崎譲優, 鎌田慎矢, 浅井圭介, 永井大樹, 宮下徳治, 三ツ石方也

Property Type: Patent
固体高分子型燃料電池の酸素分圧分布等の計測方法とその装置、並びに固体高分子型燃料電池の制御方法と制御装置

箱崎譲優, 鎌田慎矢, 浅井圭介, 永井大樹, 宮下徳治, 三ツ石方也

特許第4762603号

Property Type: Patent
ループ型ヒートパイプ

望月正孝, 川原洋司, 古川正夫, 永井大樹

Property Type: Patent
ループ型ヒートパイプ

望月正孝, 川原洋司, 古川正夫, 永井大樹

特許第3885098号

Property Type: Patent
MULTI-PHASETHERMALCONTROL APPARATUS,EVAPORATORSAND METHODS OF MANUFACTURE THEREOF

Scot N.Roberts, Arthur J.Mastropietro, Benjamin I.Furst, Eric T.Sunada, Jordan Mizerak, Hiroki Nagai, Stefano Cappucci

Property Type: Patent

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Research Projects 38

A Challenge to Measurement of Low Reynolds Number Unsteady Aerodynamics Using Localized Plasmon Resonance

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2025/04 - 2028/03
Wind Tunnel Experiment Digital Twin with Data Assimilation

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2021/04 - 2025/03
A new theory, vectorial and rotational canonical transformation, overcomes a barrier separating structural and mechanism analyses

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Research (Exploratory)

Institution: Tohoku University

2022/06/30 - 2024/03/31
自励振動型ヒートパイプの流動様式決定機構の解明とその制御による熱輸送特性向上

安藤麻紀子, 永井大樹

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(C)

Institution: 国立研究開発法人宇宙航空研究開発機構

2021/04/01 - 2024/03/31

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自励振動型ヒートパイプ（Oscillating Heat Pipe, OHP）は、内部で循環流が生じている際に高い熱輸送性能が得られる。本研究の最終目的はOHP内の流れが循環流化するメカニズムの解明と，より簡易に循環流を実現する方法の提案である。循環流化に大きく影響する因子として，本研究では特に流動抵抗に着目した。逆止弁付きOHPは順方向と逆方向で極端に流動抵抗差を設けることで，一方向循環流を実現する方法として先行研究にて実証済みである。初年度の活動では逆止弁を前提とし，逆止弁の順方向／逆方向の流動抵抗がOHPの内部流動及び熱輸送性能にどのように影響するかを，数値解析によって明らかにした。まず，逆方向流は完全封止できると仮定し，順方向流動抵抗が及ぼす影響について調べた。順方向流動抵抗が小さい場合は，OHPの蒸発部を液体スラグが高速で流れることで高い熱輸送性能が得られるのに対し，順方向流動抵抗の増加に伴い，液体スラグがOHPの凝縮部に滞留しつつ，少しずつ蒸発部へ液体を供給する様態に変化し，熱輸送性能は低下することがわかった。一方，順方向流動抵抗が増加してもスタートアップ特性への影響は殆ど無いことが確認できた。また，逆止弁をOHPの全ターンではなく間引いて設置した場合にも安定動作はするものの，逆止弁から離れたターンでは得られる整流効果が減少し，流速低下あるいは短期的な逆流が発生することが確認され，十分な循環流化効果を得るためには，全ターンに逆止弁を設けることが有効であると言える。次に，逆方向流の封止性に着目した数値解析を行ったところ，逆方向流動抵抗が順方向流動抵抗の50倍以下になると蒸発部での沸騰回数が明らかに減少し，熱輸送性能が低下する傾向があることがわかった。以上のように，循環流化と高い熱輸送性能の実現に必要な流動抵抗条件を数値解析により明らかにした。
Flow field measurement on a moving object surface using cntTSP at low Reynolds numbers

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2021/04 - 2024/03
Research on biological flexible and foldable deployable Mars airplanes

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory)

Category: Grant-in-Aid for Challenging Research (Exploratory)

Institution: Tohoku University

2021/07 - 2023/03
Novel Internal-Deformation Control to Bridge Fidelity Gap in Variable-Wing Aircraft Modeling

MAKIHARA Kanjuro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory)

Category: Grant-in-Aid for Challenging Research (Exploratory)

Institution: Tohoku University

2020/07/30 - 2022/03/31

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We established a structural analysis method that can change the fidelity and detail of the structural model of variable wing aircraft by using the innovative concept “internal deformation control”. We solved “valley of fidelity” with “internal deformation control” of controlling the deformation constraint equation that controls the internal deformation with the model expression. Through international joint research and large wind tunnel experiments, we clarified the effectiveness of the proposed method in both theoretical analysis and demonstration experiments. The significance of challenging research is (1) a research field with few previous studies and poor knowledge, and there is a budding element that challenges based on new ideas, (2) utilize new “internal deformation control”, international cooperation, and large wind tunnel experiments to realize the true multi-fidelity.
Development of measurement fusion simulation method for unsteady three-dimensional vortex flow

OBAYASHI SHIGERU

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2018/04/01 - 2021/03/31

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We developed and improved a technique for measuring fluid forces and flow fields by magnetically levitating a model in a wind tunnel, and increased our knowledge of basic fluid mechanics by investigating the fluid forces acting on a cylinder and the vortices emitted from the cylinder, and applied it to sports engineering by proposing the use of a turbo jab, which is beneficial as an introduction to javelin throwing events. In addition, we improved the efficiency of data assimilation techniques using measured values and optimized the measurement positions so that computer simulations can faithfully reproduce the flow in the wind tunnel.
New concept "local joint coordinates" to break down the barrier of flexible deployable wing model between 2-D and 3-D dimensions

MAKIHARA Kanjuro

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory)

Category: Grant-in-Aid for Challenging Research (Exploratory)

Institution: Tohoku University

2018/06/29 - 2020/03/31

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This is a challenging study to extend a 2D flexible deployable wing model to a 3D model using a new concept [local joint coordinates]. It was conceived that by appropriately introducing "extension deformation small" based on the structural characteristics of flexible wings, it is possible to define [local joint coordinates] that can express the three-dimensional deployment angle. We challenged 3D structural modeling with this new idea. To create a realistic modeling method, we conducted a wind tunnel experiment considering three-dimensional effects.
Establishment of a Method for Measuring Aerodynamic Heating in High Temperature Shock Tunnel Using Functional Molecular Sensors

Nagai Hiroki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2017/04/01 - 2020/03/31

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The purpose of the research is to develop a non-intrusive and quantitative optical measurement technique to measure the aerodynamic heating distribution flowing into the space vehicle from the high-temperature and high-pressure environment during reentry into the atmosphere. In particular, new ideas were added to the conventional Temperature-Sensitive Paint measurement technique to measure aerodynamic heating in high enthalpy flows quantitatively. Furthermore, visualization of the transition position of the boundary layer in a low-speed flow was also carried out by applying the technique used for the Temperature-Sensitive Paint with a light-shielding layer. It was shown that the technique could be applied to estimate the position with high accuracy.
Improvement of start-up characteristics of oscillating heat pipe with check valves

Ando Makiko

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

Category: Grant-in-Aid for Scientific Research (C)

Institution: Japan Aerospace EXploration Agency

2017/04/01 - 2020/03/31

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An oscillating heat pipe (OHP) with check valves is an attractive two-phase flow heat transfer device, which can remove waste heat effectively from narrow spaces. However, it has difficulty in starting up under the initial condition where the working fluid is localized in the cooling section. This study tried to improve the start-up characteristics by numerical simulations of vapor-liquid behavior in the OHP and experimental evaluations. The results showed that the start-up characteristics could be improved when the check valves were located near the cooling section, not at the center of the adiabatic section. The check valves located near the cooling section could help the working fluid to be resupplied to the heating section, resulting in successfull start-up. Additionally, this study showed that the check valve layout in a zig-zag manner could be the most balanced solution to realize both the reliable start-up and high heat transfer performance in the steady-state.
Airfoil optimization study in unsteady low Reynolds number flow

IKEDA Tomoaki, ATOBE Takashi, ASAI Keisuke, NAGAI Hiroki, KONISHI Yasufumi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

Category: Grant-in-Aid for Scientific Research (C)

Institution: Japan Aerospace EXploration Agency

2013/04/01 - 2016/03/31

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We conducted airfoil design optimization studies for low Reynolds number, rarefied atmospheric environment, such as ultra high altitude, or Mars atmospheric flight, for three years. In low Reynolds number flight, the unsteady vortical motion in relatively large scale becomes more dominant. We performed both numerical simulations and wind tunnel tests for various airfoil shapes to clarify the onset mechanism of unsteady motions. For a better aerodynamic performance, the airfoil shape near the leading edge should stay flat, while the maximum camber location should be given near the trailing edge, for very thin thickness. Our achievements were reported in academic journals and conferences.
Key technology Research and High-altitude demonstration to realize the world first Mars exploration using Airplane

NAGAI Hiroki, OYAMA Akira, TOKUTAKE Hiroshi, TAKEUCHI Shinsuke, TOYOTA Hiroyuki, OTSUKI Masatsugu, NONOMURA Taku, ANYOJI Masayuki, YONEMOTO Koichi, FUJII Kozo, ASAI Keisuke

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2012/04/01 - 2015/03/31

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In this study, we aimed for the realization of a Mars airplane which flying the Mars atmosphere. The fundamental key technology (Aerodynamic, Structure, Control, Propulsion, Power, Thermal, etc.) to realize the Mars airplane were researched and developed. As a result, about the developed individual technique, a high-performance wing and an ultra-lightweight airframe structure, etc., were able to get enough performance to let a system of the Mars airplane satisfy. In the future, we will conduct a flight demonstration test of an integrated airplane system at a high-altitude in the vicinity of 35 km on earth, where the Mars environment can be simulated; air density and temperature is almost same, and demonstrate the feasibility of the realization of the Mars airplane.
Ground experiment of the innovative sonic boom reduction technology

OBAYASHI Shigeru, KOBAYASHI Hideaki, ASAI Keisuke, NAGAI Hiroki, OGAWA Toshihiro, SAITO Tsutomu, KAWAZOE Hiromitsu, CHIBA Kazuhisa, NUMATA Daiju

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2011/04/01 - 2015/03/31

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Design and evaluation systems for supersonic vehicles are constructed in this research to develop a low-boom supersonic vehicle based on Supersonic Biplane Theory. The following experimental and numerical simulation techniques were developed: free flight experiment of three-dimensional projectiles, surface pressure distribution measurement using ultrafast response pressure-sensitive paint, a calibration technique of pressure waveforms by the multipole method, a force balance measurement system in a supersonic wind tunnel, sonic boom estimation with consideration of the real atmospheric conditions, and design optimization and exploration for unsteady phenomena.
Next-Generation Dynamic Wind-Tunnel Testing for Realizing Virtual Flight-Test Environment

ASAI Keisuke, NAGAI Hiroki, NUMATA Daiju, JIANG Xin, KONNO Atsushi, NAKAKITA Kazuyuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2010 - 2012

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The purpose of this study is to develop a next-generation dynamic wind-tunnel testing technique based on hybrid-simulation approach for studying dynamic stability of aircraft in nonlinear flight region. A new parallel-link robotic manipulator called “HEXA" has been designed, built, and used for conducting multi-degree-of-freedom dynamic wind-tunnel testing. In addition, advanced optical measurement techniques such as unsteady Pressure-Sensitive Paint and Fluorescent Mini-tuft have been developed to visualize the flow on the model moving in the flow. As a result of the experiment using these techniques, the effects of oscillation frequency and amplitude on the dynamic stability of a wing have been clarified.
火星探査航空機の研究 Competitive

System: Cooperative Research

2009/04 -
非定常圧力場可視化計測のための超高感度感圧分子センサの開発

浅井圭介, 永井大樹

Offer Organization: 日本学術振興会

System: 科学研究費助成事業挑戦的萌芽研究

Category: 挑戦的萌芽研究

Institution: 東北大学

2008 - 2009

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従来の圧力計測技術の限界を打ち破る革新的な手法として,1)信号処理や画像処理を利用した非定常計測手法と 2)ナノ多孔質膜を用いた感圧分子センサの開発に取り組んだ.今年度は感圧塗料計測の適用範囲を低速・非定常現象に拡大することを目的に,非定常計測手法として信号処理を利用したPhase-lock法および周波数解析を利用した手法の開発と高度化を,また多孔質アルミナを利用した差圧型感圧分子センサ膜の流れ場への適用を行った.合わせて感圧塗料による低速現象計測に対して理論誤差解析を行い,主要な誤差要因の特定および改善を行った.その結果以下に示す成果が得られた. ・角柱側面に周期的に生じる"ゆらぎ"をもった非定常圧力変動を基準現象として,信号処理を利用したPhase-lock法および周波数解析を利用した手法の開発と高度化を行った.その結果,これらの技術により角柱側面でピーク周波数150Hzで変動する圧力分布を振幅0.1～0.3kPaで正弦振動する圧力変動を捉えられることがわかった.加えて,低速現象計測に最適な感圧塗料の選定および信号・画像処理手法の改良を行うことで両手法の圧力計測精度や空間・位相分解能を大きく改善させ,より微小かつ高速な非定常現象への適用可能性を示した. ・流れ場中における多孔質アルミナを用いた差圧応答型PSPの特性を調べた.開発した差圧応答型PSPは,流れ場中において従来のPSPの数倍程度の圧力感度を持つことがわかった.ただし,PSPの発光は圧力に加え流速にも依存し,圧力を正確に測定するためには2つのパラメータを分離する機構やデータ処理手法を開発する必要があることがわかった.
High-accuracy estimation of aerodynamic heating in high enthalpy flowusing Temperature-Sensitive Paint and Inverse method

NAGAI Hiroki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)

Category: Grant-in-Aid for Young Scientists (B)

Institution: Tohoku University

2008 - 2009

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The objective of this study is the establishment of aerodynamic heating measurement technique using Temperature-Sensitive Paint (TSP) in high enthalpy flow with self-luminescence such as an atmospheric re-entry vehicle. First of all, the effect of model material, thickness and the limitation of spatial resolution for the heat flux distribution estimation were evaluated by laser heating test. In addition, TSP characteristics were investigated for the sensitivity with the different thickness and material, the response, the degradation. Then, this technique was applied to hypersonic wind tunnel test and the accuracy was evaluated. The results demonstrated the validity of TSP technique for aerodynamic heating measurement.
Fundamental Research for Silent Supersonic Transport Based on Supersonic Biplane Theory Competitive

OBAYASHI Shigeru, ASAI Keisuke, NAGAI Hiroki, SASOU Akihiro, KAWAZOE Hiromitsu, MATSUNO Takashi, NAKAHASHI Kazuhiro, MATSUSHIMA Kisa, JEONG Shinkyu, TSUBOI Nobuyuki, NAKAMURA Yoshiaki, MIYAJI Kouji, SATO Tetsuya, MATSUO Akiko, SAWAI Syujiro, FUJITA Kazuhisa, KOBAYASHI Hiroaki, TAGUCHI Hideyuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2007 - 2009

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Supersonic Biplane Theory is a concept of eliminating wave drag and sonic boom by using shock wave interaction between two airfoils facing each other. The following research topics are investigated in this research to construct and validate the theory : Definition of three-dimensional wing configuration and its optimization, Investigation of low speed characteristics of supersonic biplane by using CFD and EFD, Supersonic wind tunnel test of starting process of three-dimensional supersonic biplane, Free flight experiment of supersonic biplane using ballistic range.
Development of Wind Tunnel Technology for Simulating Planetary Atmospheric Flight Competitive

ASAI Keisuke, NAGAI Hiroki, SAWADA Keisuke, SAWADA Hideo

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2006 - 2008
感温塗料を用いた空力加熱計測 Competitive

System: Cooperative Research

2007/11 -
実験/計算融合によるソニックブーム推定方法の高精度化 Competitive

System: Contract Research

2007/04 -
感圧塗料を用いた表面圧力分布計測技術 Competitive

System: Contract Research

2006/10 -
感圧塗料による酸素分圧分布可視化計測技術の開発 Competitive

System: Contract Research

2006/06 -
先端技術を用いた風洞実験手法の研究 Competitive

System: Cooperative Research

2006/04 -
感圧・感温センシングのための色素連結型酸素透過性高分子の開発 Competitive

2006/04 -
機能性分子センサの低温及び高速流体への適用に関する共同研究 Competitive

System: Cooperative Research

2004/04 - 2006/03
Study on Cooling Technology for Superconducting Magnets Employed in Space-Borne Applications

NAKAI Hirotaka, KIMURA Nobuhiro, MAKIDA Yasuhiro, NAGAI Hiroki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: High Energy Accelerator Research Organization (KEK)

2004 - 2006

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Boiling phenomena of superfluid helium have been visualized by employing a cryostat with optical windows on it and a high-speed camera, and variations of film boiling modes and heat transfer coefficients have been measured in wide ranges of pressure and temperature to unveil the thermal characteristics of superfluid helium for efficient cooling of superconducting magnets. It is concluded from the experimental results that the noisy film boiling, which is the unique boiling phenomenon of saturated superfluid helium, does not appear under the microgravity environment of space, even if almost the same amount of superfluid helium is located over the heater as that under the gravity. Because of rapid growing of vapor phase, "viscous fingering" phenomenon was observed, and higher thermal conduction may be obtained by the effect of mixed phases motion. Loop heat pipes are suggested for the heat exhaust from cooling systems, since the loop heat pipes are light in weight, highly reliable, and can transfer large amount of heat. Their start-up and performance characteristics under microgravity are studied in cases of top-heating and bottom-heating. It is found out that when rather large heat was applied to the heat pipes, there was no difference in heat transfer capacity from the case when heat pipes are placed horizontally, and stable performance was observed once they had started up. Unstable performance had been sometimes observed when the heat load was small. This means the flow path of the vapor may be choked with the liquid at the outlet of the evaporator when start-up. Hence the initial distribution of the liquid may affect largely the start-up of heat pipes under the microgravity condition. The temperature control of the reservoir seems to be able to ensure the start-up of the heat pipes regardless of the initial distribution of the liquid.
感圧塗料の応用に関する研究・調査 Competitive

System: Contract Research

2005/06 -
低速領域における感圧塗料の計測法の共同研究 Competitive

System: Contract Research

2005/04 -
PSP実験によるデルタ翼Wing Rock現象の解明 Competitive

System: Cooperative Research

2005/04 -
将来型宇宙機搭載用LHPRSの研究 Competitive

System: Cooperative Research

2005/04 -
ループヒートパイプ排熱システムの研究 Competitive

System: Cooperative Research

2005/04 -
Development of Micro-scale Wind-Tunnel Technology for Micro-flow Studies Competitive

ASAI Keisuke, YU Fukunishi, NAGAI Hiroki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2004 - 2005

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In the present study, we developed two types of a micro wind tunnel capable of studying micrometer to millimeter sized flow devices. We classified our targets into two categories ; a supersonic micro wind tunnel and a micro fluid channel. The supersonic micro wind tunnel is an indraft-type Mach-2 tunnel having the test section of 10mm x 10mm. The contours of the Laval nozzle have been calculated using the method of characteristics and boundary-layer correction by the Navier-Stokes CFD calculation. Conventional techniques like pressure transducers and thermocouples cannot be used to calibrate the flow in such miniature-size wind tunnels. We used luminescent sensors like Pressure- and Temperature-Sensitive Paints (PSP/TSP). It has been confirmed that uniform flow condition is achieved in the test section during the run time on the order of several seconds. In addition to the micro supersonic tunnel, we also built a Mach-4 micro nozzle having the throat as narrow as 250 micrometers and studied the evolution of supersonic flow in the nozzle. We measured pressure and temperature fields at very low Reynolds numbers by decreasing the settling-chamber pressure. These dataset had not been available in previous works. In this experiment, we discovered a strangle phenomenon that indicated the flow was decelerated upstream of the throat section. By comparing the obtained data with 3-DNavier-Stokes CFD calculation, we found that this unusual phenomenon occurred due to viscous layers on the nozzle walls and the sidewalls. For the study of fluid flow in a micro channel, we developed micro channel flow system driven by a syringe pump. In the mixing channel, liquid from two tanks were mixed. The effects of channel geometry and the period of sinusoidal forcing on the mixing were examined experimentally. It was shown that the most effective mixing could be accomplished by stratification of two liquids. The theoretical density pattern obtained by Lattice-Boltzmann Method agreed well with the experimental data.
極低温領域で使用可能な小型軽量ループ・ヒートパイプ・システムの試作開発および研究 Competitive

System: Grant-in-Aid for Scientific Research

2003 - 2005
マイクロ流路内現象解明技術の研究 Competitive

System: Contract Research

2004/06 -
宇宙機搭載を目指した超伝導電磁石の冷却技術の研究 Competitive

System: Grant-in-Aid for Scientific Research

2003/04 -
衝撃圧縮によって誘起される超流動ヘリウム中の2種類の衝撃波及び非定常相転移の研究

永井大樹

Offer Organization: 日本学術振興会

System: 科学研究費助成事業特別研究員奨励費

Category: 特別研究員奨励費

Institution: 筑波大学

1999 - 2000

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Teaching Experience 10

Spacecraft Engineering　Tohoku University
Basic Fluid Dynamics　Tohoku University
Fluid Dynamics　Tohoku University
Advanced Space Fluid Dynamics　Tohoku University
Mechanical and Aerospace Engineering Training I, II　Tohoku University
The Science of Shock Waves　Tohoku University
Flight Dynamics　Tohoku University
Mathematical Physics Exercise II　Tohoku University
Aerospace fluid dynamics　Tohoku University
Mechanical and Aerospace Engineering Experiment I, II　Tohoku University

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Social Activities 5

文化フォーラム in 仙台「見えない宇宙をみる科学の眼」

2011/12/18 -

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講演会の主催一般の人に宇宙とその可視化について分かり易く講演する．
第18回科学講演会

2011/09/04 -

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科学講演会の主催・ペットボトルロケットの製作・打ち上げ
第16回科学講演会

2009/09/05 -

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科学講演会の主催・ペットボトルロケットの製作・打ち上げ
第15回科学講演会

2008/09/07 -

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科学講演会の主催・ペットボトルロケットの製作・打ち上げ
第14回科学講演会

2007/09/02 -

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科学講演会の主催・ペットボトルロケットの製作・打ち上げ

Other 3

バリスティックレンジ試験委託

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再突入カプセル形状の飛翔体を用いたバリスティックレンジ自由飛行試験を実施し、光学観測によって飛翔体挙動を記録する。東北大と機構のバリスティックレンジ試験結果を比較することで、設備間特性と遷音速不安定性を把握する。
バドミントンシャトルコックの飛翔特性の解明と航空工学分野への応用

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シャトルコックのダイナミクスを考慮した状態で飛翔の空力的研究を実施し、その成果による高速飛翔体の減速機構の新機軸を展開する
揚力装置組込み翼の試作と風洞試験における空力データ取得

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本課題の試験研究実施責任者らは、流体における境界層のはく離を防止する制御システムを開発し、特許登録を受けている。この技術を航空機の翼に応用すれば、高揚力装置組込み翼の開発が可能となるが、どの程度の効果があるかは実証されてはいなかった。そこで、開発した制御システムを組み込んだ翼模型を試作するとともに、風洞試験により翼性能を取得し、開発した装置の効果を定量的に示すことを目的とする。得られた具体的なデータをもとに、航空機メーカーに特許のライセンスを試みる。