TOHOKU UNIVERSITY Researchers

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Naofumi Ohnishi

Section

Graduate School of Engineering

Job title

Professor

Degree

博士（工学）（大阪大学）
修士（工学）（大阪大学）

researchmap

https://researchmap.jp/read0054904

J-GLOBAL ID

200901053338838691

Research History 5

2016/04 - Present

Tohoku University　Professor
2008/10 - 2016/03

Department of Aerospace Engineering, Tohoku University　Associate Professor
2007/04 - 2008/09

Center for Research Strategy and Support, Tohoku University　Associate Professor
2006/10 - 2007/03

Lawrence Livermore National Laboratory　Research Fellow
2001/04 - 2007/03

Department of Aerospace Engineering, Tohoku University　Research Associate

Education 3

Osaka University　Graduate School, Division of Engineering　電気工学

- 2001/03/23
Osaka University　Graduate School, Division of Engineering　電気工学

- 1998/03/25
Osaka University　Faculty of Engineering　電気工学科

- 1996/03/25

Committee Memberships 5

日本航空宇宙学会　レーザー宇宙航空応用検討委員会

2012/04 - 2014/03
日本航空宇宙学会　レーザー宇宙航空応用検討委員会

2012/04 - 2014/03
日本航空宇宙学会　論文編集委員

2012/04 -
日本航空宇宙学会　空気力学部門委員

2012/04 -
日本航空宇宙学会北部支部　幹事

2007/04 -

Professional Memberships 6

日本機械学会

2019/08 - Present
American Physical Society
The American Institute of Aeronautics and Astronautics
The Physical Society of Japan
The Japan Society of Plasma Science and Nuclear Fusion Research
The Japan Society for Aeronautical and Space Sciences

︎Show all ︎Show first 5

Research Interests 8

プラズマアクチュエータ
Supernova Explosion
X-ray Laser
Inertial Fusion
Plasma Application
Laser Propulsion
Radiation Hydrodynamics
Computational Fluid Dynamics

Research Areas 4

Natural sciences / Theoretical studies related to particle-, nuclear-, cosmic ray and astro-physics /
Energy / Basic plasma science /
Aerospace, marine, and maritime Engineering / Aerospace engineering /
Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Fluid engineering /

Papers 182

Role of surface discharge dynamics in the generation of electrohydrodynamic force: toward performance improvement of dielectric barrier discharge plasma actuators

Shintaro Sato, Naofumi Ohnishi

Journal of Physics D: Applied Physics　58　(14)　143002-143002　2025/02/20
Publisher: IOP Publishing
DOI： 10.1088/1361-6463/adb3af 　

ISSN： 0022-3727

eISSN： 1361-6463

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Abstract Dielectric barrier discharge (DBD) plasma actuators are devices that actively control the airflow using nonequilibrium atmospheric-pressure plasmas, showing promise for practical applications in the field of aerospace engineering. Numerous studies have revealed the dynamics of surface discharge and the process of generating electrohydrodynamic (EHD) force in detail. The performance of DBD plasma actuators has improved continuously over the past 20 years. However, there is a need for further improvement in EHD force generation to enable the practical applications of DBD plasma actuators. In this review, we provide insights that contribute to the development of a high-performance DBD plasma actuator by reviewing previous studies focused on revealing the surface discharge and EHD force generation processes. The foundations of the discharge process in DBD plasma actuators are briefly described from the perspectives of experiments and numerical simulations. We also reviewed various strategies for improving EHD force generation by optimizing the geometric structure and the applied voltage waveform as well as by controlling the surface charge accumulation. Improving EHD force generation and its efficiency is a fundamental research area to realize the practical applications of a novel active airflow control device that uses nonequilibrium plasmas.
Application of proper orthogonal decomposition to flow fields around various geometries and reduced-order modeling

Yuto Nakamura, Shintaro Sato, Naofumi Ohnishi

Computer Methods in Applied Mechanics and Engineering　432　117340-117340　2024/12
Publisher: Elsevier BV
DOI： 10.1016/j.cma.2024.117340 　

ISSN： 0045-7825
Integrating sheath and radiation-based acceleration using scaling coefficients for tailoring radiation dominant hybrid acceleration

Harihara Sudhan Kumar, Masayuki Takahashi, Yasuhiro Kuramitsu, Naofumi Ohnishi

Scientific Reports　14　(1)　2024/09/28
Publisher: Springer Science and Business Media LLC
DOI： 10.1038/s41598-024-72623-5 　

eISSN： 2045-2322
A hybrid simulation integrating molecular dynamics and particle-in-cell methods for improved laser-target interaction Peer-reviewed

Harihara Sudhan Kumar, Masayuki Takahashi, Yasuhiro Kuramitsu, Takumi Minami, Hiromitsu Kiriyama, Yuji Fukuda, Naofumi Ohnishi

High Energy Density Physics　101148-101148　2024/08
Publisher: Elsevier BV
DOI： 10.1016/j.hedp.2024.101148 　

ISSN： 1574-1818
Dynamic instability in lift-type reentry capsule at supersonic flow

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.
Proper orthogonal decomposition method of constructing a reduced-order model for solving partial differential equations with parametrized initial values

Yuto Nakamura, Shintaro Sato, Naofumi Ohnishi

Partial Differential Equations in Applied Mathematics　100654-100654　2024/02
Publisher: Elsevier BV
DOI： 10.1016/j.padiff.2024.100654 　

ISSN： 2666-8181
Ionic wind generation through coplanar discharge: A plasma actuator without exposed electrodes

Shintaro Sato, Mahoro Sakurai, Naofumi Ohnishi

AIP Advances　13　(6)　2023/06/01
Publisher: AIP Publishing
DOI： 10.1063/5.0150335 　

eISSN： 2158-3226

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This study demonstrates the successful induction of a unidirectional ionic wind by adding an embedded electrode in a coplanar discharge, thus breaking the generation of a symmetrical electric field. The strategy for the ionic wind generation is based on separating the ionization process and the charged-particle acceleration process. Conventional plasma actuators used to induce an ionic wind typically incorporate exposed electrodes that pose a risk of unexpected airflow disturbance and reduce durability due to oxidation. However, the coplanar discharge-based, exposed-electrodeless plasma actuator developed in this study overcomes these issues. The coplanar discharge generates a diffused and uniform surface discharge, a desirable attribute for plasma actuators. The ionic wind velocity generated by this coplanar discharge plasma actuator is comparable to that generated by conventional plasma actuators when applying a square-waveform bias voltage to the additional electrode. Furthermore, this study emphasizes the significance of the phase difference between the repetitive pulses for generating coplanar discharge and the square-waveform voltage for accelerating the charged particles.
Numerical simulation of atmospheric-pressure surface dielectric barrier discharge on a curved dielectric with a curvilinear mesh

Hideto Tamura, Shintaro Sato, Naofumi Ohnishi

Journal of Physics D: Applied Physics　56　(4)　045202-045202　2023/01/26
Publisher: IOP Publishing
DOI： 10.1088/1361-6463/aca61d 　

ISSN： 0022-3727

eISSN： 1361-6463

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Abstract A numerical simulation method for atmospheric-pressure surface dielectric barrier discharge (DBD) is presented using a structured curvilinear mesh that is fitted to a curved dielectric surface. The numerical method is based on the plasma fluid model with general coordinate transformation, which is widely used in the field of the computational fluid dynamics. The calculations of a potential distribution formed by a line electrode and a planar surface DBD are performed to confirm the validity of the proposed method. We conducted numerical simulations of the DBD on a wavy surface using the proposed method to investigate the characteristics of the DBD on a curved surface. The propagation velocity of the discharge front and the electric field strength of the discharge front changed depending on the surface shape. The proposed method enables the calculation of the DBD on a complex surface and widens the application range of the numerical simulation in the field of discharge physics.
Robustness of large-area suspended graphene under interaction with intense laser

Y. Kuramitsu, T. Minami, T. Hihara, K. Sakai, T. Nishimoto, S. Isayama, Y. T. Liao, K. T. Wu, W. Y. Woon, S. H. Chen, Y. L. Liu, S. M. He, C. Y. Su, M. Ota, S. Egashira, A. Morace, Y. Sakawa, Y. Abe, H. Habara, R. Kodama, L. N. K. Döhl, N. Woolsey, M. Koenig, H. S. Kumar, N. Ohnishi, M. Kanasaki, T. Asai, T. Yamauchi, K. Oda, Ko. Kondo, H. Kiriyama, Y. Fukuda

Scientific Reports　12　(1)　2022/12
Publisher: Springer Science and Business Media LLC
DOI： 10.1038/s41598-022-06055-4 　

eISSN： 2045-2322
The Effect of SiC-MOSFET Characteristics on the Performance of Dielectric Barrier Discharge Plasma Actuators with Two-Stroke Charge Cycle Operation

Shintaro Sato, Tomoki Yoshikawa, Naofumi Ohnishi

Actuators　11　(11)　333-333　2022/11/17
Publisher: MDPI AG
DOI： 10.3390/act11110333 　

eISSN： 2076-0825

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The low-voltage operation of a dielectric-barrier-discharge (DBD) plasma actuator with a simple electric circuit has the potential to put it into industrial applications. However, there is an issue that the efficiency of the low-voltage operated DBD plasma actuator is lower than that of the high-voltage operated one. In this study, the characteristics of silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs), which are used in the electric circuit, are investigated with a focus on the on-state resistance. The on-state resistance of the SiC-MOSFET affects the rise time of the applied voltage in our experimental condition. The energy consumption by applying a pulse voltage to the DBD plasma actuator increases with increasing the on-state resistance. Flow visualization with particle image velocimetry measurement reveals that a DBD plasma actuator with the SiC-MOSFET whose on-state resistance is the lowest induces the highest velocity of the ionic wind. Also, low on-state resistance is preferable in terms of the thrust-to-power ratio. These findings contribute to the development of an optimal power supply for DBD plasma actuators for industrial applications.
Enhancement of electrohydrodynamic force with AC bias voltage in three-electrode dielectric barrier discharge plasma actuators

Shintaro Sato, Mahoro Sakurai, Naofumi Ohnishi

Journal of Applied Physics　132　(11)　113301-113301　2022/09/21
Publisher: AIP Publishing
DOI： 10.1063/5.0100696 　

ISSN： 0021-8979

eISSN： 1089-7550

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A novel dielectric barrier discharge (DBD) plasma-actuator module with an exposed electrode and two covered electrodes was developed to enhance electrohydrodynamic force generation based on the concept that it separates the ionization and acceleration processes. The conventional three-electrode configuration of the DBD plasma actuator suffers from unexpected spark discharge between the exposed electrodes, thereby failing to strengthen the electric field intensity for accelerating charged particles or generating a stable ionic wind. In this study, a third electrode was embedded in the dielectric layer to prevent spark discharge. Furthermore, an alternating current (AC) waveform was employed as the bias voltage, which was applied to the third electrode, instead of the direct current (DC) voltage used in a conventional DBD plasma actuator. Induced flow visualization using particle image velocimetry technique revealed that the DC bias voltage forms a weak ionic wind in the proposed DBD plasma actuator owing to the electric field screening effect, and the ionic wind periodically appears when the polarity of the voltage is reversed by applying an AC-bias voltage. The velocity of the ionic wind increases with increasing frequency and the AC bias voltage amplitude. Also, decreasing the distance between the second and third electrodes results in ionic wind enhancement. The results obtained in this study provide insights into the drastic improvement in the performance of DBD plasma actuators with the enhancement of the electric field intensity for charged particle acceleration.
Fabrication and performance evaluation of full-inkjet-printed dielectric-barrier-discharge plasma actuators

Shintaro Sato, Kazuki Nishida, Toshimitsu Hirai, Masaki Ito, Hirofumi Teramae, Masaki Matsubara, Kiyoshi Kanie, Naofumi Ohnishi

Sensors and Actuators A: Physical　344　113751-113751　2022/09
Publisher: Elsevier BV
DOI： 10.1016/j.sna.2022.113751 　

ISSN： 0924-4247
Plasma propagation via radiation transfer in millimeter-wave discharge under subcritical condition Peer-reviewed

S Suzuki, C Kato, M Takahashi, N Ohnishi

Journal of Physics: Conference Series　2207　(1)　012046-012046　2022/03/01
Publisher: IOP Publishing
DOI： 10.1088/1742-6596/2207/1/012046 　

ISSN： 1742-6588

eISSN： 1742-6596

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Abstract An improved model was proposed to reduce a computational cost for subcritical millimeter-wave discharge. The proposed model was able to reproduce the plasma-front propagation via radiation transport as similar to the conventional model, and the plasma-front propagation speed was in agreement with the previous simulation. An electron transport effect by neutral fluid advection, which has been introduced into the conventional model, does not affect the propagation speed. By using the presented model, a computational time was reduced by 35%, which was suitable for a multi-dimensional simulation in the future.
High-power laser experiment forming a supercritical collisionless shock in a magnetized uniform plasma at rest

R. Yamazaki, S. Matsukiyo, T. Morita, S. J. Tanaka, T. Umeda, K. Aihara, M. Edamoto, S. Egashira, R. Hatsuyama, T. Higuchi, T. Hihara, Y. Horie, M. Hoshino, A. Ishii, N. Ishizaka, Y. Itadani, T. Izumi, S. Kambayashi, S. Kakuchi, N. Katsuki, R. Kawamura, Y. Kawamura, S. Kisaka, T. Kojima, A. Konuma, R. Kumar, T. Minami, I. Miyata, T. Moritaka, Y. Murakami, K. Nagashima, Y. Nakagawa, T. Nishimoto, Y. Nishioka, Y. Ohira, N. Ohnishi, M. Ota, N. Ozaki, T. Sano, K. Sakai, S. Sei, J. Shiota, Y. Shoji, K. Sugiyama, D. Suzuki, M. Takagi, H. Toda, S. Tomita, S. Tomiya, H. Yoneda, T. Takezaki, K. Tomita, Y. Kuramitsu, Y. Sakawa

Physical Review E　105　(2)　2022/02/11
Publisher: American Physical Society (APS)
DOI： 10.1103/physreve.105.025203 　

ISSN： 2470-0045

eISSN： 2470-0053
Kinetic theory of double layers driven by temperature anisotropy in a non-homogeneous magnetic field

Harihara Sudhan Kumar, Masayuki Takahashi, Chinami Kato, Yuya Oshio, Naofumi Ohnishi

Journal of Applied Physics　130　(16)　2021/10/28

DOI： 10.1063/5.0065665 　

ISSN： 0021-8979

eISSN： 1089-7550
Surface-charge control strategy for enhanced electrohydrodynamic force in dielectric barrier discharge plasma actuators

Shintaro Sato, Kodai Mitsuhashi, Tomoki Enokido, Atsushi Komuro, Akira Ando, Naofumi Ohnishi

Journal of Physics D: Applied Physics　54　(45)　455203-455203　2021/08/06
Publisher: IOP Publishing
DOI： 10.1088/1361-6463/ac1b5d 　

ISSN： 0022-3727

eISSN： 1361-6463
Connections between the modes of a nonlinear dynamical system on a manifold

Shintaro Sato, Hiroki Sakamoto, Naofumi Ohnishi

Physical Review E　103　(6)　2021/06/09
Publisher: American Physical Society (APS)
DOI： 10.1103/physreve.103.062210 　

ISSN： 2470-0045

eISSN： 2470-0053
Development of a flexible dielectric-barrier-discharge plasma actuator fabricated by inkjet printing using silver nanoparticles-based ink

Shintaro Sato, Tomoki Enokido, Kenichiro Ashikawa, Masaki Matsubara, Kiyoshi Kanie, Naofumi Ohnishi

Sensors and Actuators A: Physical　112823-112823　2021/05
Publisher: Elsevier BV
DOI： 10.1016/j.sna.2021.112823 　

ISSN： 0924-4247
Fabrication of a multi-stage plasma synthetic jet actuator using printed electronics

Shintaro Sato, Tomoki Enokido, Naofumi Ohnishi

AIP Advances　11　(4)　045105-045105　2021/04/01
Publisher: AIP Publishing
DOI： 10.1063/5.0047709 　

eISSN： 2158-3226
Numerical Analysis of Shock Speed Attenuation in Expansion Tube

Hiroki Sakamoto, Shintaro Sato, Naofumi Ohnishi

AIAA Scitech 2021 Forum　2021/01/11
Publisher: American Institute of Aeronautics and Astronautics
DOI： 10.2514/6.2021-0058 　
Performance Improvement of Dielectric Barrier Discharge Plasma Actuator with Two-Stroke Cycle Operation

Shintaro Sato, Tomoki Enokido, Kenichiro Ashikawa, Naofumi Ohnishi

AIAA Scitech 2021 Forum　2021/01/11
Publisher: American Institute of Aeronautics and Astronautics
DOI： 10.2514/6.2021-1492 　
Computational Study of Discharge Process in Plasma Actuator for Enhanced Electrohydrodynamic Force Generation toward Low-Voltage Operation

Shintaro SATO, Haruki FURUKAWA, Masayuki TAKAHASHI, Naofumi OHNISHI

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN　19　(1)　17-23　2021
Publisher: Japan Society for Aeronautical and Space Sciences
DOI： 10.2322/tastj.19.17 　

eISSN： 1884-0485
A study on the macroscopic self-organized structure of high-power millimeter-wave breakdown plasma

Yasuhisa Oda, Masayuki Takahashi, Naofumi Ohnishi, Kimiya Komurasaki, Keishi Sakamoto, Tsuyoshi Imai

Plasma Sources Science and Technology　29　(7)　075010-075010　2020/07/29
Publisher: IOP Publishing
DOI： 10.1088/1361-6595/ab9d67 　

eISSN： 1361-6595
Experimental demonstration of low-voltage operated dielectric barrier discharge plasma actuators using SiC MOSFETs Peer-reviewed

Shintaro Sato, Yuta Ozawa, Atsushi Komuro, Taku Nonomura, Keisuke Asai, Naofumi Ohnishi

Journal of Physics D: Applied Physics　2020/06/29
Publisher: IOP Publishing
DOI： 10.1088/1361-6463/aba0e1 　

ISSN： 0022-3727

eISSN： 1361-6463
A fast solver of plasma fluid model in dielectric-barrier-discharge simulation Peer-reviewed

Shintaro Sato, Takashi Shiroto, Masayuki Takahashi, Naofumi Ohnishi

Plasma Sources Science and Technology　29　(7)　2020/06/09
Publisher: IOP Publishing
DOI： 10.1088/1361-6595/ab9b18 　

ISSN： 0963-0252

eISSN： 1361-6595
Gas propellant dependency of plasma structure and thrust performance of microwave rocket

Masayuki Takahashi, Naofumi Ohnishi

Journal of Applied Physics　125　(16)　163303-163303　2019/04/28
Publisher: AIP Publishing
DOI： 10.1063/1.5053086 　

ISSN： 0021-8979

eISSN： 1089-7550
Numerical study of discharge and thrust generation in a microwave rocket

Masayuki Takahashi, Naofumi Ohnishi

AIAA Scitech 2019 Forum　2019
Publisher: American Institute of Aeronautics and Astronautics Inc, AIAA
DOI： 10.2514/6.2019-1242 　
Numerical study of unsteady high enthalpy flow in an expansion tube

Kazumasa Kitazono, Masayuki Takahashi, Naofumi Ohnishi, Hideyuki Tanno

AIAA Scitech 2019 Forum　2019
Publisher: American Institute of Aeronautics and Astronautics Inc, AIAA
DOI： 10.2514/6.2019-1392 　
Discharge process and gas heating effect in nanosecond-pulse-driven plasma actuator

Shintaro Sato, Masayuki Takahashi, Naofumi Ohnishi

AIAA Scitech 2019 Forum　2019
Publisher: American Institute of Aeronautics and Astronautics Inc, AIAA
DOI： 10.2514/6.2019-1001 　
Successively accelerated ionic wind with integrated dielectric-barrier-discharge plasma actuator for low-voltage operation Peer-reviewed

Sato Shintaro, Furukawa Haruki, Komuro Atsushi, Takahashi Masayuki, Ohnishi Naofumi

Scientific Reports　9　5813　2019

DOI： 10.1038/s41598-019-42284-w 　

ISSN： 2045-2322
Gas-species-dependence of microwave plasma propagation under external magnetic field Peer-reviewed

Masayuki Takahashi, Naofumi Ohnishi

JOURNAL OF APPLIED PHYSICS　124　173301-1-173301-11　2018/11
Numerical Study of Discharge Physics Induced by Subcritical Millimeter Wave

Kanta Hamasaki, Masayuki Takahashi, Naofumi Ohnishi

International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz　2018-　2018/10/25
Publisher: IEEE Computer Society
DOI： 10.1109/IRMMW-THz.2018.8510111 　

ISSN： 2162-2035 2162-2027
Numerical Study of Millimeter-Wave Discharge and Application to Launching System for Small Satellites

Masayuki Takahashi, Naofumi Ohnishi

International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz　2018-　2018/10/25
Publisher: IEEE Computer Society
DOI： 10.1109/IRMMW-THz.2018.8510247 　

ISSN： 2162-2035 2162-2027
Frequency dependence of atmospheric millimeter wave breakdown plasma Peer-reviewed

Yasuhisa Oda, Masayuki Takahashi, Kuniyoshi Tabata, Naofumi Ohnishi, Kimiya Komurasak, Keishi Sakamoto

International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz　2018-September　2018/10/25

DOI： 10.1109/IRMMW-THz.2018.8510051 　

ISSN： 2162-2027

eISSN： 2162-2035
Quadratic conservative scheme for relativistic Vlasov–Maxwell system Peer-reviewed

Takashi Shiroto, Naofumi Ohnishi, Yasuhiko Sentoku

Journal of Computational Physics　379　32-50　2018/10

DOI： 10.1016/j.jcp.2018.10.041 　

ISSN： 0021-9991

eISSN： 1090-2716
Structure-preserving operators for thermal-nonequilibrium hydrodynamics Peer-reviewed

Takashi Shiroto, Soshi Kawai, Naofumi Ohnishi

Journal of Computational Physics　364　1-17　2018/07/01
Publisher: Academic Press Inc.
DOI： 10.1016/j.jcp.2018.03.008 　

ISSN： 1090-2716 0021-9991

eISSN： 1090-2716
Separation control on an airfoil using repetitive laser pulses Peer-reviewed

Masayuki Takahashi, Naofumi Ohnishi

AIAA Aerospace Sciences Meeting, 2018　(210059)　2018
Publisher: American Institute of Aeronautics and Astronautics Inc, AIAA
DOI： 10.2514/6.2018-1430 　
Induced flow simulation with detailed discharge modeling in dielectric-barrier-discharge plasma actuator Peer-reviewed

Shintaro Sato, Masayuki Takahashi, Naofumi Ohnishi

AIAA Aerospace Sciences Meeting, 2018　(210059)　2018
Publisher: American Institute of Aeronautics and Astronautics Inc, AIAA
DOI： 10.2514/6.2018-1293 　
Computational Study of Body Force Production Process and Performance Improvement in Dielectric-Barrier-Discharge Plasma Actuator Peer-reviewed

Sato Shintaro, Takahashi Masayuki, Ohnishi Naofumi

Transactions of the Japan Society for Aeronautical and Space Science, Aerospace Technology Japan　16　550　2018

DOI： 10.2322/tastj.16.550 　
Open-front approach of a microwave rocket sustained by a resonant magnetic field Peer-reviewed

Masayuki Takahashi, Naofumi Ohnishi

Journal of Propulsion and Power　34　(3)　762-771　2018
Publisher: American Institute of Aeronautics and Astronautics Inc.
DOI： 10.2514/1.B36621 　

ISSN： 0748-4658
Validation of radiative transfer computation with Monte Carlo method for ultra-relativistic background flow Peer-reviewed

Ayako Ishii, Naofumi Ohnishi, Hiroki Nagakura, Hirotaka Ito, Shoichi Yamada

JOURNAL OF COMPUTATIONAL PHYSICS　348　612-633　2017/11

DOI： 10.1016/j.jcp.2017.07.038 　

ISSN： 0021-9991

eISSN： 1090-2716
Finite-volume-concept-based Padé-type filters Peer-reviewed

Takashi Shiroto, Soshi Kawai, Naofumi Ohnishi

Journal of Computational Physics　349　215-219　2017/08/18
A study of RF power station for microwave rocket launch system Peer-reviewed

Y. Oda, T. Imai, K. Shimamura, M. Fukunari, H. Katsurayama, N. Ohnishi, K. Komurasaki

EPJ Web of Conferences　149　2017/08/04
Publisher: EDP Sciences
DOI： 10.1051/epjconf/201714902010 　

ISSN： 2100-014X 2101-6275
Generation of counter-streaming plasmas for collisionless shock experiment Peer-reviewed

Y. Sakawa, T. Ide, T. Morita, K. Tomita, K. Uchino, Y. Kuramitsu, N. Ohnishi, H. Takabe

HIGH ENERGY DENSITY PHYSICS　23　207-211　2017/06

DOI： 10.1016/j.hedp.2017.04.007 　

ISSN： 1574-1818

eISSN： 1878-0563
Experimental demonstration of bow-shock instability and its numerical analysis Peer-reviewed

Y. Kikuchi, N. Ohnishi, K. Ohtani

SHOCK WAVES　27　(3)　423-430　2017/05

DOI： 10.1007/s00193-016-0669-5 　

ISSN： 0938-1287

eISSN： 1432-2153
Enhanced electrohydrodynamic force generation in a two-stroke cycle dielectric-barrier-discharge plasma actuator Peer-reviewed

Shintaro Sato, Masayuki Takahashi, Naofumi Ohnishi

APPLIED PHYSICS LETTERS　110　(19)　194101-1-194101-4　2017/05

DOI： 10.1063/1.4983370 　

ISSN： 0003-6951

eISSN： 1077-3118
Joule-heating-supported plasma filamentation and branching during subcritical microwave irradiation Peer-reviewed

Masayuki Takahashi, Yoshiaki Kageyama, Naofumi Ohnishi

AIP ADVANCES　7　(5)　055206-1-055206-7　2017/05

DOI： 10.1063/1.4983569 　

ISSN： 2158-3226
Analysis of unstable mode structures in hypersonic boundary layer Peer-reviewed

Hiroaki Tatematsu, Yousuke Ogino, Naofumi Ohnishi, Hideyuki Tanno

AIAA SciTech Forum - 55th AIAA Aerospace Sciences Meeting　2017
Publisher: American Institute of Aeronautics and Astronautics Inc.
DOI： 10.2514/6.2017-1695 　
Inuence of voltage waveform on electrohydrodynamic force in a dielectric-barrier-discharge plasma actuator Peer-reviewed

Shintaro Sato, Naofumi Ohnishi

AIAA SciTech Forum - 55th AIAA Aerospace Sciences Meeting　2017
Publisher: American Institute of Aeronautics and Astronautics Inc.
DOI： 10.2514/6.2017-1804 　
Trajectory and Thermal Analyses for Disk-Shaped Dust Particles Through a Shock Layer Peer-reviewed

Yousuke Ogino, Yoshihiro Toki, Keisuke Nakajima, Naofumi Ohnishi

JOURNAL OF SPACECRAFT AND ROCKETS　54　(1)　191-198　2017/01

DOI： 10.2514/1.A33439 　

ISSN： 0022-4650

eISSN： 1533-6794
Numerical demonstration of high-Z doping scheme on ignition-relevant scale implosion Peer-reviewed

T. Shiroto, N. Ohnishi, A. Sunahara, S. Fujioka, A. Sasaki

PHYSICS OF PLASMAS　23　(12)　122705-1-122705-8　2016/12

DOI： 10.1063/1.4972546 　

ISSN： 1070-664X

eISSN： 1089-7674
TIME EVOLUTION OF KELVIN-HELMHOLTZ VORTICES ASSOCIATED WITH COLLISIONLESS SHOCKS IN LASER-PRODUCED PLASMAS Peer-reviewed

Y. Kuramitsu, A. Mizuta, Y. Sakawa, H. Tanji, T. Ide, T. Sano, M. Koenig, A. Ravasio, A. Pelka, H. Takabe, C. D. Gregory, N. Woolsey, T. Moritaka, S. Matsukiyo, Y. Matsumoto, N. Ohnishi

ASTROPHYSICAL JOURNAL　828　(2)　93-1-93-10　2016/09

DOI： 10.3847/0004-637X/828/2/93 　

ISSN： 0004-637X

eISSN： 1538-4357
Plasma filamentation and shock wave enhancement in microwave rockets by combining low-frequency microwaves with external magnetic field Peer-reviewed

Masayuki Takahashi, Naofumi Ohnishi

JOURNAL OF APPLIED PHYSICS　120　(6)　063303-1-063303-16　2016/08

DOI： 10.1063/1.4960805 　

ISSN： 0021-8979

eISSN： 1089-7550
Theoretical modeling of pulse discharge cycle in dielectric barrier discharge plasma actuator Peer-reviewed

Shintaro Sato, Naofumi Ohnishi

Japanese Journal of Applied Physics　55　(7)　07LD04-1-07LD04-7　2016/06/13
Publisher: Institute of Physics
DOI： 10.7567/JJAP.55.07LD04 　

ISSN： 0021-4922

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Simple models based on two-dimensional simulations are proposed to estimate intervals of periodically observed current pulses with a positive-going voltage in a dielectric barrier discharge plasma actuator. There are two distinct peaks in one streamer discharge; one is related to the formation of an ion cloud and the other is related to a filamentary discharge that is identified as a streamer. Simulation results show that the intervals of the current pulses depend on the slope of the applied voltage. For the ion-cloud formation phase, we model the time evolution of electron number density at the exposed electrode with ionization frequency. For the ion-cloud expansion phase, a positive ion cylinder model is proposed to estimate the electric field generated by surface charge on the dielectric. These models well reproduce the discharge intervals obtained in the numerical simulations.
Numerical study of breakdown pattern induced by an intense microwave under nitrogen and argon gases Peer-reviewed

Masayuki Takahashi, Naofumi Ohnishi

Japanese Journal of Applied Physics　55　(7)　07LD02-1-07LD02-6　2016/06/03
Publisher: Institute of Physics
DOI： 10.7567/JJAP.55.07LD02 　

ISSN： 0021-4922

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Filamentary plasma induced by microwave beam irradiation was reproduced in nitrogen and argon by combining fluid or particle plasma models with electromagnetic wave propagation. Transport coefficients used in the fluid model are estimated from particle simulation to maintain consistency of the breakdown structure between the fluid and particle models. A discrete structure was obtained using the one-dimensional (1D) fluid model, because a standing wave is generated in front of the plasma when the incident microwave beam is reflected by the overcritical plasma, which agrees with the breakdown structure obtained using the 1D particle model. A 2D plasma filament was also reproduced using the fluid model in nitrogen and argon. Reflection of the incident microwave in argon becomes stronger than that in nitrogen because of the denser argon plasma. Change in filament shape is induced in argon because the electric field is deformed at the plasma tip owing to stronger wave reflection from the neighboring filament. The propagation speed of the plasma front becomes larger in argon breakdown because of the larger ionization frequency and the larger diffusion coefficient.
Flash K alpha radiography of laser-driven solid sphere compression for fast ignition Peer-reviewed

H. Sawada, S. Lee, T. Shiroto, H. Nagatomo, Y. Arikawa, H. Nishimura, T. Ueda, K. Shigemori, A. Sunahara, N. Ohnishi, F. N. Beg, W. Theobald, F. Perez, P. K. Patel, S. Fujioka

APPLIED PHYSICS LETTERS　108　(25)　254101-1-254101-4　2016/06

DOI： 10.1063/1.4954383 　

ISSN： 0003-6951

eISSN： 1077-3118
Radiation Magneto-Hydrodynamics Simulations for Laser- Produced Collisionless Shock Experiment

A. Ishii, N. Ohnishi, R. Yamazaki, Y. Shoji, S. Tomiya, Y. Sakawa, Y. Hara, H. Shimogawara, S. Matsukiyo, T. Morita, K. Tomita, S. Tanaka, Y. Teraki

2016/05
Fast ignition realization experiment with high-contrast kilo-joule peta-watt LFEX laser and strong external magnetic field Peer-reviewed

Shinsuke Fujioka, Yasunobu Arikawa, Sadaoki Kojima, Tomoyuki Johzaki, Hideo Nagatomo, Hiroshi Sawada, Seung Ho Lee, Takashi Shiroto, Naofumi Ohnishi, Alessio Morace, Xavier Vaisseau, Shohei Sakata, Yuki Abe, Kazuki Matsuo, King Fai Farley Law, Shota Tosaki, Akifumi Yogo, Keisuke Shigemori, Yoichiro Hironaka, Zhe Zhang, Atsushi Sunahara, Tetsuo Ozaki, Hitoshi Sakagami, Kunioki Mima, Yasushi Fujimoto, Kohei Yamanoi, Takayoshi Norimatsu, Shigeki Tokita, Yoshiki Nakata, Junji Kawanaka, Takahisa Jitsuno, Noriaki Miyanaga, Mitsuo Nakai, Hiroaki Nishimura, Hiroyuki Shiraga, Kotaro Kondo, Mathieu Bailly-Grandvaux, Claudio Bellei, Joao Jorge Santos, Hiroshi Azechi

PHYSICS OF PLASMAS　23　(5)　056308-1-056308-11　2016/05

DOI： 10.1063/1.4948278 　

ISSN： 1070-664X

eISSN： 1089-7674
Toward the Generation of Magnetized Collisionless Shocks with High-Power Lasers Peer-reviewed

Yoshitaka SHOJI, Ryo YAMAZAKI, Sara TOMITA, Yushiro KAWAMURA, Yutaka OHIRA, Satoshi TOMIYA, Yoichi SAKAWA, Takayoshi SANO, Yukiko HARA, Sarana KONDO, Hiroshi SHIMOGAWARA, Shuichi MATSUKIYO, Taichi MORITA, Kentaro TOMITA, Hitoki YONEDA, Kazunori NAGAMINE, Yasuhiro KURAMITSU, Toseo MORITAKA, Naofumi OHNISHI, Takayuki UMEDA, Hideaki TAKABE

Plasma and Fusion Research　11　3401031-3401031　2016/03
Publisher: Japan Society of Plasma Science and Nuclear Fusion Research
DOI： 10.1585/pfr.11.3401031 　

eISSN： 1880-6821
Numerical study on wall pressure over cone region of blunt-nosed body in high enthalpy shock tunnel HIEST Peer-reviewed

Tomoaki Ishihara, Yousuke Ogino, Takumi Kino, Naofumi Ohnishi

AEROSPACE SCIENCE AND TECHNOLOGY　50　256-265　2016/03

DOI： 10.1016/j.ast.2015.12.015 　

ISSN： 1270-9638

eISSN： 1626-3219
Model experiment of magnetic field amplification in laser-produced plasmas via the Richtmyer-Meshkov instability Peer-reviewed

Y. Kuramitsu, N. Ohnishi, Y. Sakawa, T. Morita, H. Tanji, T. Ide, K. Nishio, C. D. Gregory, J. N. Waugh, N. Booth, R. Heathcote, C. Murphy, G. Gregori, J. Smallcombe, C. Barton, A. Diziere, M. Koenig, N. Woolsey, Y. Matsumoto, A. Mizuta, T. Sugiyama, S. Matsukiyo, T. Moritaka, T. Sano, H. Takabe

PHYSICS OF PLASMAS　23　(3)　032126-1-032126-6　2016/03

DOI： 10.1063/1.4944925 　

ISSN： 1070-664X

eISSN： 1089-7674
Global stability analysis on cone models under the conditions of the HIEST experiments

Yuji Matsuse, Masaru Saijo, Tomoaki Ishihara, Yousuke Ogino, Naofumi Ohnishi, Hideyuki Tanno

54th AIAA Aerospace Sciences Meeting　2016
Publisher: American Institute of Aeronautics and Astronautics Inc, AIAA
DOI： 10.2514/6.2016-0596 　
Computation of hypersonic flow over a reentry capsule with roughness induced transition

Tomoaki Ishihara, Yousuke Ogino, Naofumi Ohnishi, Keisuke Sawada, Hideyuki Tanno

54th AIAA Aerospace Sciences Meeting　2016
Publisher: American Institute of Aeronautics and Astronautics Inc, AIAA
21pCB-6 Multi-dimensional RHD simulations for optimal design of solid ball implosion

Shiroto T., Lee S., Fujioka S., Ohnishi N., Sawada H.

Meeting Abstracts of the Physical Society of Japan　71　943-943　2016
Publisher: The Physical Society of Japan (JPS)
DOI： 10.11316/jpsgaiyo.71.1.0_943 　

ISSN： 2189-079X
Thrust Performance of Microwave Rocket at Low Ambient Pressure

TAKAHASHI Masayuki, OHNISHI Naofumi

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN　14　(30)　Pb_209-Pb_215　2016
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/tastj.14.Pb_209 　

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<p>A particle model of plasma was coupled with electromagnetic wave propagation to reproduce a filamentary structure and diffusive pattern in a microwave breakdown. The thrust performance of a microwave rocket was estimated by combining discharge calculation and computational fluid dynamics (CFD). An external magnetic field is applied to the discharge volume to improve thrust performance for low ambient pressure by combination of magnetic confinement and resonance heating technique. The magnetic field suppresses the propagation speed of the ionization front because the electron cannot cross the magnetic field at lower pressure, whereas propagation speed increases with decreased ambient pressure when no magnetic field is applied. The energy absorption rate increases when electron cyclotron resonance (ECR) occurs with the corresponding magnetic field, which improves the thrust performance of the microwave rocket.</p>
Development of a conservative scheme for the one-fluid two-temperature model

Shiroto Takashi, Kawai Soshi, Ohnishi Naofumi

Meeting Abstracts of the Physical Society of Japan　71　591-591　2016
Publisher: The Physical Society of Japan
DOI： 10.11316/jpsgaiyo.71.2.0_591 　
Reverse plasma motion driven by moderately screened rotating electric field in an electrodeless plasma thruster Peer-reviewed

Naofumi Ohnishi, Ryosuke Nomura, Takahiro Nakamura, Hiroyuki Nishida

JAPANESE JOURNAL OF APPLIED PHYSICS　55　(1)　016202-1-016202-7　2016/01

DOI： 10.7567/JJAP.55.016202 　

ISSN： 0021-4922

eISSN： 1347-4065
Shock Formation by Plasma Filaments of Microwave Discharge under Atmospheric Pressure Peer-reviewed

Masayuki Takahashi, Naofumi Ohnishi

8TH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS (IFSA 2013)　688　012119-1-012119-4　2016

DOI： 10.1088/1742-6596/688/1/012119 　

ISSN： 1742-6588
Dependence of Ablative Rayleigh-Taylor Instability on High-Z Dopant Concentration Peer-reviewed

Takashi Shiroto, Naofumi Ohnishi, Atsushi Sunahara, Shinsuke Fujioka

8TH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS (IFSA 2013)　688　012109-1-012109-4　2016

DOI： 10.1088/1742-6596/688/1/012109 　

ISSN： 1742-6588
Spherical shock in the presence of an external magnetic field Peer-reviewed

Y. Kuramitsu, S. Matsukiyo, S. Isayama, D. Harada, T. Oyama, R. Fujino, Y. Sakawa, T. Morita, Y. Yamaura, T. Ishikawa, T. Moritaka, T. Sano, K. Tomita, R. Shimoda, Y. Sato, K. Uchino, A. Pelka, R. Crowston, N. Woolsey, G. Gregori, M. Koenig, D. W. Yuan, C. L. Yin, Y. T. Li, K. Zhang, J. Y. Zhong, F. L. Wang, N. Ohnishi, K. Nagamine, H. Yoneda, H. Takabe

8TH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS (IFSA 2013)　688　012056-1-012056-4　2016

DOI： 10.1088/1742-6596/688/1/012056 　

ISSN： 1742-6588
Thomson scattering measurement of a collimated plasma jet generated by a high-power laser system Peer-reviewed

T. Ishikawa, Y. Sakawa, T. Morita, Y. Yamaura, Y. Kuramitsu, T. Moritaka, T. Sano, R. Shimoda, K. Tomita, K. Uchino, S. Matsukiyo, A. Mizuta, N. Ohnishi, R. Crowston, N. Woolsey, H. Doyle, G. Gregori, M. Koenig, C. Michaut, A. Pelka, D. Yuan, Y. Li, K. Zhang, J. Zhong, F. Wang, H. Takabe

8TH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS (IFSA 2013)　688　012098-1-012098-4　2016

DOI： 10.1088/1742-6596/688/1/012098 　

ISSN： 1742-6588
Computational Study of Magnetic Field Amplification in Laser-Produced Shock Waves Relevant to Supernova Remnants Peer-reviewed

Ayako Ishii, Shiori Kishita, Naofumi Ohnishi, Yasuhiro Kuramitsu, Taichi Morita, Youichi Sakawa, Hideaki Takabe

8TH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS (IFSA 2013)　688　012035-1-012035-4　2016

DOI： 10.1088/1742-6596/688/1/012035 　

ISSN： 1742-6588
High-density implosion via suppression of Rayleigh Taylor instability Peer-reviewed

Takashi Shiroto, Naofumi Ohnishi, Atsushi Sunahara, Shinsuke Fujioka, Akira Sasaki

9TH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS (IFSA 2015)　717　012051-1-012051-4　2016

DOI： 10.1088/1742-6596/717/1/012051 　

ISSN： 1742-6588
Beam-Riding Flight of a Laser Propulsion Vehicle Using Actively Controlled Pulse Peer-reviewed

Masayuki Takahashi, Naofumi Ohnishi

JOURNAL OF PROPULSION AND POWER　32　(1)　237-250　2016/01

DOI： 10.2514/1.B35631 　

ISSN： 0748-4658

eISSN： 1533-3876
Numerical analysis of hydrodynamic instability in magnetized laser ablation flow Peer-reviewed

Naofumi Ohnishi, Ayako Ishii, Yasuhiro Kuramitsu, Taichi Morita, Youichi Sakawa, Hideaki Takabe

HIGH ENERGY DENSITY PHYSICS　17　18-23　2015/12

DOI： 10.1016/j.hedp.2014.11.006 　

ISSN： 1574-1818

eISSN： 1878-0563
Identical algorithm of radiative transfer across ultrarelativistic shock in different inertial frames Peer-reviewed

Ayako Ishii, Naofumi Ohnishi, Hiroki Nagakura, Hirotaka Ito, Shoichi Yamada

HIGH ENERGY DENSITY PHYSICS　17　85-91　2015/12

DOI： 10.1016/j.hedp.2014.11.002 　

ISSN： 1574-1818

eISSN： 1878-0563
Bow-shock instability induced by Helmholtz resonator-like feedback in slipstream Peer-reviewed

Naofumi Ohnishi, Yosuke Sato, Yuta Kikuchi, Kiyonobu Ohtani, Kanako Yasue

PHYSICS OF FLUIDS　27　(6)　066103-1-066103-16　2015/06

DOI： 10.1063/1.4922086 　

ISSN： 1070-6631

eISSN： 1089-7666
Study of Capsule Geometry for Dust Sample Acquisition During Mars Atmospheric Entry Peer-reviewed

Yousuke Ogino, Ippei Terata, Keisuke Nakajima, Naofumi Ohnishi, Kazuhisa Fujita

JOURNAL OF SPACECRAFT AND ROCKETS　52　(2)　375-382　2015/03

DOI： 10.2514/1.A32827 　

ISSN： 0022-4650

eISSN： 1533-6794
Uncertainty quantification study of non-equilibrium viscous shock-layer

Takumi Kino, Kosuke Totani, Tomoaki Ishihara, Yousuke Ogino, Naofumi Ohnishi

53rd AIAA Aerospace Sciences Meeting　2015
Publisher: American Institute of Aeronautics and Astronautics Inc, AIAA
DOI： 10.2514/6.2015-0983 　
18pCP-9 Multi-dimensional implosion simulations and verification of detailed opacity model

Shiroto Takashi, Ohnishi Naofumi, Sunahara Atsushi, Fujioka Shinsuke, Sasaki Akira

Meeting Abstracts of the Physical Society of Japan　70　678-678　2015
Publisher: The Physical Society of Japan (JPS)
DOI： 10.11316/jpsgaiyo.70.2.0_678 　

ISSN： 2189-079X
24aBH-8 The effect of atomic process model in implosion simulation with high-Z dopant

Shiroto Takashi, Ohnishi Naofumi, Sunahara Atsushi, Fujioka Shinsuke, Sasaki Akira

Meeting Abstracts of the Physical Society of Japan　70　930-930　2015
Publisher: The Physical Society of Japan (JPS)
DOI： 10.11316/jpsgaiyo.70.1.0_930 　

ISSN： 2189-079X
LES computation of turbulent heat flux on reentry capsule afterbody with forced transition Peer-reviewed

Tomoaki Ishihara, Yousuke Ogino, Naofumi Ohnishi, Hideyuki Tanno

53rd AIAA Aerospace Sciences Meeting　2015
Publisher: American Institute of Aeronautics and Astronautics Inc, AIAA
DOI： 10.2514/6.2015-0210 　
Theoretical and Numerical Studies of Dynamic Scaling of a Six-Degree-of-Freedom Laser Propulsion Vehicle Peer-reviewed

Masayuki Takahashi, Naofumi Ohnishi

INTERNATIONAL JOURNAL OF AEROSPACE ENGINEERING　2015　801371-1-801371-12　2015

DOI： 10.1155/2015/801371 　

ISSN： 1687-5966

eISSN： 1687-5974
Numerical Study on Abnormal Heat Flux Augmentation in High Enthalpy Shock Tunnel (HIEST) Peer-reviewed

Tomoaki Ishihara, Yousuke Ogino, Naofumi Ohnishi, Hideyuki Tanno

TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES　58　(6)　319-326　2015

DOI： 10.2322/tjsass.58.319 　

ISSN： 0549-3811
Computational studies for plasma filamentation by magnetic field in atmospheric microwave discharge Peer-reviewed

Masayuki Takahashi, Naofumi Ohnishi

APPLIED PHYSICS LETTERS　105　(22)　223504-1-223504-5　2014/12

DOI： 10.1063/1.4903232 　

ISSN： 0003-6951

eISSN： 1077-3118
Experimental study on heat flux augmentation in high-enthalpy shock tunnels

Hideyuki Tanno, Tomoyuki Komuro, Naofumi Ohnishi, Tomoaki Ishihara, Yousuke Ogino, Keisuke Sawada

AIAA AVIATION 2014 -11th AIAA/ASME Joint Thermophysics and Heat Transfer Conference　2014
Publisher: American Institute of Aeronautics and Astronautics Inc.
DOI： 10.2514/6.2014-2548 　
Numerical analysis on aerothermodynamic characteristics of blunt-nosed cone in free-piston shock tunnel HIEST

Tomoaki Ishihara, Reika Aizawa, Yousuke Ogino, Naofumi Ohnishi, Keisuke Sawada, Hideyuki Tanno

52nd Aerospace Sciences Meeting　2014
Publisher: American Institute of Aeronautics and Astronautics Inc.
PIC-MCC Simulation of Electrodeless Plasma Thruster with Rotating Electric Field Peer-reviewed

Ryosuke NOMURA, Naofumi OHNISHI, Takahiro NAKAMURA, Hiroyuki NISHIDA

Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan　12　(29)　Pb_79-Pb_84　2014
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/tastj.12.Pb_79 　

ISSN： 1884-0485

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Two-dimensional simulations of Lissajous acceleration were conducted by a code based on Particle-In-Cell (PIC) method and Monte Carlo Collision (MCC) method for understanding plasma motion inaccelerationarea of an electrodeless plasma thruster and for finding the optimal condition. Obtained results showthat azimuthal current depends on a ratio of electron drift radius to plasma region length, and peak value is in proportion to AC frequency. To eliminate a disturbance on rotating mode due to electron cyclotron motion, the cyclotron frequency should be much higher than the AC frequency. When the high density plasma reduces electric field penetration, the azimuthal current is suppressed in a low level. In order to improve the electric field penetration, we should apply the high magnetic field and the high AC frequency. When a ratio of the collision frequency between electron and neutral argon to the cyclotron frequency is lower than 0.01, collisional loss of the azimuthal current is little or nothing.
Beaming Flight of Repetitive-Pulse Powered Vehicle for Satellite Launch Peer-reviewed

Masayuki TAKAHASHI, Naofumi OHNISHI

Transactions of the Japan Society for Aeronautical and Space Sciences, Aerospace Technology Japan　12　(29)　Pb_97-Pb_102　2014
Publisher: THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
DOI： 10.2322/tastj.12.Pb_97 　

ISSN： 1884-0485

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To present a feasibility of high-altitude flight of a laser-propelled vehicle at supersonic speed, we have developed a flight simulator which has fluid-orbit coupling calculation module to reproduce impulsive flight reaction driven by blast waves. By high-power energy transmission through arrayed lasers together with the genetic algorithm (GA) controlled sub-laser, the supersonic flight is successfully achieved in the simulation for 32.5-g vehicle, while the angular offset should be suppressed as small as possible. Rather than translational position, controlling angular offsets by the GA operation is especially important to attain the km-order flight on the premise of the active control. Additionally, the vehicle weight, the vehicle size, and the input energy are scaled up to assess the stable flight of 10-kg vehicle. The active control technique has enough possibility to launch kg-order vehicle at supersonic regime with the optimized beaming strategy.
Material dependence of shock waves in laser-produced Counter-streaming plasmas

Y Yamaura, Y. Sakawa, Y Kuramitsu, T Morita, T. Ishikawa, T. Moritaka, T. Sano, R. Shimoda, K. Tomita, K. Uchino, S. Matsukiyo, A. Mizuta, N. Ohnishi, R. Crowston, N. Woolsey, H. Doyle, G. Gregori, A. Ravasio, A. Pelka, M. Koenig, C.Michaut, D. Yuan, Y. Li, K. Zhang, J. Zhong, F. Wang, H.Takabe

2013/08
Laboratory astrophysical experiments using Gekko XII laser system

Y. Sakawa, Y. Kuramitsu, T. Morita, T. Ishikawa, Y. Yamaura, T. Moritaka, T. Sano, H.Takabe, R. Shimoda, K. Tomita, K. Uchino, S. Matsukiyo, A. Mizuta, N. Ohnishi, R. Crowston, N. Woolsey, H. Doyle, G. Gregori, A. Ravasio, A. Pelka, M. Koenig, C. Michaut, D. Yuan, Y. Li, K. Zhang, J. Zhong, F. Wang, A. Spitkovsky, N. L. Kugland, J. S. Ross, H.-S. Park, B. Remington

2013/08
Parallel computing of radiative transfer in relativistic jets using Monte Carlo method Peer-reviewed

Ayako Ishii, Naofumi Ohnishi, Hiroki Nagakura, Hirotaka Ito, Shoichi Yamada

HIGH ENERGY DENSITY PHYSICS　9　(2)　280-287　2013/06

DOI： 10.1016/j.hedp.2013.01.002 　

ISSN： 1574-1818
Numerical study on anomalous heating over blunt-body in free-piston shock tunnel HIEST

Tomoaki Ishihara, Yousuke Ogino, Naofumi Ohnishi, Keisuke Sawada, Hideyuki Tanno

51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2013　2013
Publisher: American Institute of Aeronautics and Astronautics Inc.
DOI： 10.2514/6.2013-909 　
Supersonic and stable flight of beam riding vehicle using optimized multiple pulses

Masayuki Takahashi, Naofumi Ohnishi

51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2013　2013
A fitting formula for radiative cooling based on non-local thermodynamic equilibrium population from weakly-ionized air plasma Peer-reviewed

Yousuke Ogino, Atsushi Nagano, Tomoaki Ishihara, Naofumi Ohnishi

24TH IUPAP CONFERENCE ON COMPUTATIONAL PHYSICS (IUPAP-CCP 2012)　454　012080-1-012080-10　2013

DOI： 10.1088/1742-6596/454/1/012080 　

ISSN： 1742-6588
Radiation hydrodynamics simulation of high-Z doped ICF targets Peer-reviewed

Takashi Shiroto, Naofumi Ohnishi, Atsushi Sunahara, Shinsuke Fujioka

Journal of Physics: Conference Series　454　(1)　012008-1-012008-6　2013
Publisher: Institute of Physics Publishing
DOI： 10.1088/1742-6596/454/1/012008 　

ISSN： 1742-6596 1742-6588

eISSN： 1742-6596
Fluid-orbit coupling calculation for flight analysis of impulsively driven laser vehicle Peer-reviewed

Masayuki Takahashi, Naofumi Ohnishi

24TH IUPAP CONFERENCE ON COMPUTATIONAL PHYSICS (IUPAP-CCP 2012)　454　012004-1-012004-7　2013

DOI： 10.1088/1742-6596/454/1/012004 　

ISSN： 1742-6588
Development of laser ablation plasma by anisotropic self-radiation Peer-reviewed

Naofumi Ohnishi, Atsushi Sunahara

IFSA 2011 - SEVENTH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS　59　06005　2013

DOI： 10.1051/epjconf/20135906005 　

ISSN： 2100-014X
Formation of counterstreaming plasmas for collisionless shock experiment Peer-reviewed

T. Ide, Y. Sakawa, Y. Kuramitsu, T. Morita, H. Tanji, K. Nishio, M. Kuwada, H. Ide, K. Tsubouchi, S. Shimazaki, T. Taguchi, C. Gregory, A. Diziere, M. Nakatsutsumi, M. Koenig, N. Ohnishi, H. Takabe

IFSA 2011 - SEVENTH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS　59　15002　2013

DOI： 10.1051/epjconf/20135915002 　

ISSN： 2100-014X
Computational study of microwave-induced ionization process using PIC-MCC method Peer-reviewed

Yasuyuki Okuno, Naofumi Ohnishi

IFSA 2011 - SEVENTH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS　59　19005　2013

DOI： 10.1051/epjconf/20135919005 　

ISSN： 2100-014X
Feasibility study of the standing accretion shock instability experiment at the National Ignition Facility Peer-reviewed

Timothy Handy, Tomasz Plewa, Bruce A. Remington, R. Paul Drake, Carolyn C. Kuranz, Naofumi Ohnishi, Hideaki Takabe

HIGH ENERGY DENSITY PHYSICS　8　(4)　331-340　2012/12

DOI： 10.1016/j.hedp.2012.09.002 　

ISSN： 1574-1818
Toward an accurate numerical simulation of radiation hydrodynamics in laser ablation plasmas Peer-reviewed

Naofumi Ohnishi

HIGH ENERGY DENSITY PHYSICS　8　(4)　341-348　2012/12

DOI： 10.1016/j.hedp.2012.09.003 　

ISSN： 1574-1818

eISSN： 1878-0563
Laboratory investigations on the origins of cosmic rays Peer-reviewed

Y. Kuramitsu, Y. Sakawa, T. Morita, T. Ide, K. Nishio, H. Tanji, H. Aoki, S. Dono, C. D. Gregory, J. N. Waugh, N. Woolsey, A. Diziere, A. Pelka, A. Ravasio, B. Loupias, M. Koenig, S. A. Pikuz, Y. T. Li, Y. Zhang, X. Liu, J. Y. Zhong, J. Zhang, G. Gregori, N. Nakanii, K. Kondo, Y. Mori, E. Miura, R. Kodama, Y. Kitagawa, K. Mima, K. A. Tanaka, H. Azechi, T. Moritaka, Y. Matsumoto, T. Sano, A. Mizuta, N. Ohnishi, M. Hoshino, H. Takabe

PLASMA PHYSICS AND CONTROLLED FUSION　54　(12)　124049-1-124049-7　2012/12

DOI： 10.1088/0741-3335/54/12/124049 　

ISSN： 0741-3335

eISSN： 1361-6587
Computational study of shock wave control by pulse energy deposition Peer-reviewed

N. Ohnishi, M. Tate, Y. Ogino

SHOCK WAVES　22　(6)　521-531　2012/11

DOI： 10.1007/s00193-012-0407-6 　

ISSN： 0938-1287

eISSN： 1432-2153
Beam Riding Performance of Asymmetrically Propelled Laser Vehicle Peer-reviewed

Masayuki Takahashi, Naofumi Ohnishi

AIAA JOURNAL　50　(11)　2600-2608　2012/11

DOI： 10.2514/1.J051822 　

ISSN： 0001-1452
Laboratory Astrophysics with Lasers: Turbulent Electromagnetic Field Associated with Collisionless shocks Peer-reviewed

Y. Kuramitsu, Y. Sakawa, T. Morita, T. Moritaka, T. Sano, Y. Matsumoto, A. Akira, N. Ohnishi, H. Takabe

Review of Laser Engineering　41　20-24　2012/09
Kelvin-Helmholtz Turbulence Associated with Collisionless Shocks in Laser Produced Plasmas Peer-reviewed

Y. Kuramitsu, Y. Sakawa, S. Dono, C. D. Gregory, S. A. Pikuz, B. Loupias, M. Koenig, J. N. Waugh, N. Woolsey, T. Morita, T. Moritaka, T. Sano, Y. Matsumoto, A. Mizuta, N. Ohnishi, H. Takabe

PHYSICAL REVIEW LETTERS　108　(19)　195004　2012/05

DOI： 10.1103/PhysRevLett.108.195004 　

ISSN： 0031-9007
Performance analysis of beam riding vehicle with motion synchronized laser pulse

Masayuki Takahashi, Naofumi Ohnishi

43rd AIAA Plasmadynamics and Lasers Conference 2012　2012
Neutron Star Kicks Affected by Standing Accretion Shock Instability for Core-Collapse Supernovae Peer-reviewed

Wakana Iwakami Nakano, Kei Kotake, Naofumi Ohnishi, Shoichi Yamada, Keisuke Sawada

DEATH OF MASSIVE STARS: SUPERNOVAE AND GAMMA-RAY BURSTS　(279)　337-338　2012

DOI： 10.1017/S1743921312013233 　

ISSN： 1743-9213
PIC Simulation of Electrodeless Plasma Thruster with Rotating Electric Field Peer-reviewed

Ryosuke Nomura, Naofumi Ohnishi, Hiroyuki Nishida

28TH INTERNATIONAL SYMPOSIUM ON RAREFIED GAS DYNAMICS 2012, VOLS. 1 AND 2　1501　1431-1436　2012

DOI： 10.1063/1.4769707 　

ISSN： 0094-243X
Toward Hybrid Simulation of Flow Generation in DBD Plasma Actuator Peer-reviewed

Kazuya Sugimoto, Naofumi Ohnishi

28TH INTERNATIONAL SYMPOSIUM ON RAREFIED GAS DYNAMICS 2012, VOLS. 1 AND 2　1501　1408-1415　2012

DOI： 10.1063/1.4769704 　

ISSN： 0094-243X
Explosive Nucleosynthesis in the Neutrino-driven Aspherical Supernova Explosion of a Non-rotating 15 M _sun Star with Solar Metallicity Peer-reviewed

Fujimoto, Shin-ichiro, Kotake, Kei, Hashimoto, Masa-aki, Ono, Masaomi, Ohnishi, Naofumi

The Astrophysical Journal　738　61　2011/09

DOI： 10.1088/0004-637X/738/1/61 　

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We investigate explosive nucleosynthesis in a non-rotating 15 M _sun star with solar metallicity that explodes by a neutrino-heating supernova (SN) mechanism aided by both standing accretion shock instability (SASI) and convection. To trigger explosions in our two-dimensional hydrodynamic simulations, we approximate the neutrino transport with a simple light-bulb scheme and systematically change the neutrino fluxes emitted from the protoneutron star. By a post-processing calculation, we evaluate abundances and masses of the SN ejecta for nuclei with a mass number <=70, employing a large nuclear reaction network. Aspherical abundance distributions, which are observed in nearby core-collapse SN remnants, are obtained for the non-rotating spherically symmetric progenitor, due to the growth of a low-mode SASI. The abundance pattern of the SN ejecta is similar to that of the solar system for models whose masses range between (0.4-0.5) M _sun of the ejecta from the inner region (<=10, 000 km) of the precollapse core. For the models, the explosion energies and the ⁵⁶Ni masses are ~= 10⁵¹erg and (0.05-0.06) M _sun, respectively; their estimated baryonic masses of the neutron star are comparable to the ones observed in neutron-star binaries. These findings may have little uncertainty because most of the ejecta is composed of matter that is heated via the shock wave and has relatively definite abundances. The abundance ratios for Ne, Mg, Si, and Fe observed in the Cygnus loop are reproduced well with the SN ejecta from an inner region of the 15 M _sun progenitor....
EFFECTS OF ROTATION ON STOCHASTICITY OF GRAVITATIONAL WAVES IN THE NONLINEAR PHASE OF CORE-COLLAPSE SUPERNOVAE Peer-reviewed

Kei Kotake, Wakana Iwakami-Nakano, Naofumi Ohnishi

ASTROPHYSICAL JOURNAL　736　(2)　124　2011/08

DOI： 10.1088/0004-637X/736/2/124 　

ISSN： 0004-637X
A collisional-radiative code for computing air plasma in high enthalpy flow Peer-reviewed

Y. Ogino, N. Ohnishi

SHOCK WAVES　21　(3)　289-299　2011/06

DOI： 10.1007/s00193-011-0328-9 　

ISSN： 0938-1287

eISSN： 1432-2153
Temperature measurements of electrostatic shocks in laser-produced counter-streaming plasmas Peer-reviewed

Morita, T., Sakawa, Y., Kuramitsu, Y., Tanji, H., Aoki, H., Ide, T., Shibata, S., Onishi, N., Gregory, C., Diziere, A., Waugh, J., Woolsey, N., Sano, Y., Shiroshita, A., Shigemori, K., Ozaki, N., Kimura, T., Miyanishi, K., Kodama, R., Koenig, M., Takabe, H.

Astrophysics and Space Science　336　(1)　283-286　2011

DOI： 10.1007/s10509-010-0525-5 　

ISSN： 0004-640X 1572-946X
Three-Dimensional Numerical Analysis for Posture Stability of Laser Propulsion Vehicle Peer-reviewed

Masayuki Takahashi, Naofumi Ohnishi

BEAMED ENERGY PROPULSION: SEVENTH INTERNATIONAL SYMPOSIUM　1402　2011

DOI： 10.1063/1.3657022 　

ISSN： 0094-243X
Computational Study of Discharge Processes in DBD Plasma Actuators Invited Peer-reviewed

Shoichi EBATO, Yousuke OGINO, Naofumi OHNISHI

The Journal of Space Technology and Science　25　(2)　19-33　2011
Collisionless shockwave generation in counter-streaming plasmas using Gekko XII HIPER laser Peer-reviewed

Takao Ide, Youichi Sakawa, Yasuhiro Kuramitsu, Taichi Morita, Hiroki Tanji, Kento Nishio, Tsunehiko Kato, Naofumi Ohnishi, Christopher D. Gregory, Nigel Woolsey, Alexandra Diziere, Michel Koenig, Shoujun Wang, Quanli Dong, Yutong Li, Hideaki Takabe

Plasma and Fusion Research　6　(1)　2404057　2011

DOI： 10.1585/pfr.6.2402057 　

ISSN： 1880-6821
Aspherical abundance distribution of ejecta from neutrino-driven core collapse supernova Peer-reviewed

Fujimoto, Shin-Ichiro, Kotake, Kei, Hashimoto, Masa-Aki, Ono, Masaomi, Ohnishi, Naofumi

THE 10TH INTERNATIONAL SYMPOSIUM ON ORIGIN OF MATTER AND EVOLUTION OF GALAXIES: OMEG-2010. AIP Conference Proceedings　1269　472-474　2010/08

DOI： 10.1063/1.3485205 　
Explosive nucleosynthesis in a neutrino-driven core collapse supernova Peer-reviewed

Fujimoto, Shin-Ichiro, Kotake, Kei, Hashimoto, Masa-Aki, Ono, Masaomi, Ohnishi, Naofumi

TOURS SYMPOSIUM ON NUCLEAR PHYSICS AND ASTROPHYSICS-VII. AIP Conference Proceedings　1238　169-174　2010/06

DOI： 10.1063/1.3455922 　
Implicit Discontinuous Galerkin Method for RANS Simulation Utilizing Pointwise Relaxation Algorithm Peer-reviewed

Kanako Yasue, Michiko Furudate, Naofumi Ohnishi, Keisuke Sawada

COMMUNICATIONS IN COMPUTATIONAL PHYSICS　7　(3)　510-533　2010/03

DOI： 10.4208/cicp.2009.09.055 　

ISSN： 1815-2406
Thermochemical nonequilibrium flow computation of drag reduction by pulsed laser

Masami Tate, Yousuke Ogino, Naofumi Ohnishi

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition　2010
ENumerical analysis of momentum transfer process in DBD plasma actuator

Shoichi Ebato, Yousuke Ogino, Naofumi Ohnishi

41st AIAA Plasmadynamics and Lasers Conference　2010
Characterization of heat-wave propagation through laser-driven Ti-doped underdense plasma Peer-reviewed

Minoru Tanabe, Hiroaki Nishimura, Naofumi Ohnishi, Kevin B. Fournier, Shinsuke Fujioka, Atsushi Iwamae, Stephanie B. Hansen, Keiji Nagai, Frederic Girard, Michel Primout, Bruno Villette, Didier Brebion, Kunioki Mima

HIGH ENERGY DENSITY PHYSICS　6　(1)　89-94　2010/01

DOI： 10.1016/j.hedp.2009.06.006 　

ISSN： 1574-1818
A new attempt for radiation hydrodynamics simulation with anisotropic and non-equilibrium distribution Peer-reviewed

N. Ohnishi, K. Sugai, Y. Ogino

SIXTH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS, PARTS 1-4　244　022078　2010

DOI： 10.1088/1742-6596/244/2/022078 　

ISSN： 1742-6588
RAY-TRACING ANALYSIS OF ANISOTROPIC NEUTRINO RADIATION FOR ESTIMATING GRAVITATIONAL WAVES IN CORE-COLLAPSE SUPERNOVAE Peer-reviewed

Kei Kotake, Wakana Iwakami, Naofumi Ohnishi, Shoichi Yamada

ASTROPHYSICAL JOURNAL　704　(2)　951-963　2009/10

DOI： 10.1088/0004-637X/704/2/951 　

ISSN： 0004-637X

eISSN： 1538-4357
Spiral mode of standing accretion shock instability in core-collapse supernovae Peer-reviewed

Wakana Iwakami, Naofumi Ohnishi, Kei Kotake, Shoichi Yamada, Keisuke Sawada

ASTROPHYSICS AND SPACE SCIENCE　322　(1-4)　43-47　2009/08

DOI： 10.1007/s10509-008-9957-6 　

ISSN： 0004-640X
EFFECTS OF ROTATION ON STANDING ACCRETION SHOCK INSTABILITY IN NONLINEAR PHASE FOR CORE-COLLAPSE SUPERNOVAE Peer-reviewed

WAKANA IWAKAMI, KEI KOTAKE, NAOFUMI OHNISHI, SHOICHI YAMADA, AND KEISUKE, SAWADA

THE ASTROPHYSICAL JOURNAL　700　232-242　2009/07/20
Baroclinic vortex influence on wave drag reduction induced by pulse energy deposition Peer-reviewed

Yousuke Ogino, Naofumi Ohnishi, Shinichi Taguchi, Keisuke Sawada

PHYSICS OF FLUIDS　21　(6)　066102　2009/06

DOI： 10.1063/1.3147932 　

ISSN： 1070-6631
Implicit Large Eddy Simulation of Two-Dimensional Homogeneous Turbulence Using Weighted Compact Nonlinear Scheme Peer-reviewed

Keiichi Ishiko, Naofumi Ohnishi, Kazuyuki Ueno, Keisuke Sawada

JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME　131　(6)　061401　2009/06

DOI： 10.1115/1.3077141 　

ISSN： 0098-2202

eISSN： 1528-901X
STOCHASTIC NATURE OF GRAVITATIONAL WAVES FROM SUPERNOVA EXPLOSIONS WITH STANDING ACCRETION SHOCK INSTABILITY Peer-reviewed

Kei Kotake, Wakana Iwakami, Naofumi Ohnishi, Shoichi Yamada

ASTROPHYSICAL JOURNAL LETTERS　697　(2)　L133-L136　2009/06

DOI： 10.1088/0004-637X/697/2/L133 　
Three-dimensional simulations of standing accretion shock instability in core-collapse supernovae Peer-reviewed

Wakana Iwakami, Kei Kotake, Naofumi Ohnishi, Shoichi Yamada, Keisuke Sawada

ASTROPHYSICAL JOURNAL　678　(2)　1207-1222　2008/05

DOI： 10.1086/533582 　

ISSN： 0004-637X
Numerical computation of radiative heating environment for Huygens probe entry flight Peer-reviewed

Hiroshi Sawa, Shingo Matstryama, Naofumi Ohnishi, Michiko Furudate, Keisuke Sawada

JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER　22　(2)　140-149　2008/04

DOI： 10.2514/1.31654 　

ISSN： 0887-8722
Computational study of thrust generation from laser-driven blast wave Peer-reviewed

Naofumi Ohnishi, Yousuke Ogino

BEAMED ENERGY PROPULSION　997　419-+　2008

ISSN： 0094-243X
Standing accretion shock instability: numerical simulations of core-collapse supernova Peer-reviewed

N. Ohnishi, W. Iwakami, K. Kotake, S. Yamada, S. Fujioka, H. Takabe

5TH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS (IFSA2007)　112　042018　2008

DOI： 10.1088/1742-6596/112/4/042018 　

ISSN： 1742-6588
Numerical Methods for Three-Dimensional Analysis of Shock Instability in Supernova Cores Peer-reviewed

Wakana Iwakami, Naofumi Ohnishi, Kei Kotake, Shoichi Yamada, Keisuke Sawada

5TH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS (IFSA2007)　112　042021　2008

DOI： 10.1088/1742-6596/112/4/042021 　

ISSN： 1742-6588
Numerical analysis of nanograin collision by classical molecular dynamics Peer-reviewed

N. Ohnishi, E. M. Bringa, B. A. Remington, G. Gilmer, R. Minich, Y. Yamaguchi, A. G. G. M. Tielens

5TH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS (IFSA2007)　112　042017　2008

DOI： 10.1088/1742-6596/112/4/042017 　

ISSN： 1742-6588
Numerical study of laser-induced blast wave coupled with unsteady ionization processes Peer-reviewed

Y. Ogino, N. Ohnishi, K. Sawada

5TH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS (IFSA2007)　112　042019　2008

DOI： 10.1088/1742-6596/112/4/042019 　

ISSN： 1742-6588
Supersonic heat wave propagation in laser-produced underdense plasma for efficient x-ray generation Peer-reviewed

Minoru Tanabe, Hiroaki Nishimura, Shinsuke Fujioka, Keiji Nagai, Atsushi Iwamae, Naofumi Ohnishi, Kevin B. Fournier, Frederic Girard, Michel Primout, Bruno Villette, Mike Tobin, Kunioki Mima

5TH INTERNATIONAL CONFERENCE ON INERTIAL FUSION SCIENCES AND APPLICATIONS (IFSA2007)　112　022076　2008

DOI： 10.1088/1742-6596/112/2/022076 　

ISSN： 1742-6588
Inelastic neutrino-helium scatterings and standing accretion shock instability in core-collapse supernovae Peer-reviewed

Naofumi Ohnishi, Kei Kotake, Shoichi Yamada

ASTROPHYSICAL JOURNAL　667　(1)　375-381　2007/09

DOI： 10.1086/520755 　

ISSN： 0004-637X

eISSN： 1538-4357
Excitation of g-modes in a proto-neutron star by the standing accretion shock instability Peer-reviewed

Shijun Yoshida, Naofumi Ohnishi, Shoichi Yamada

ASTROPHYSICAL JOURNAL　665　(2)　1268-1276　2007/08

DOI： 10.1086/519303 　

ISSN： 0004-637X
Numerical analysis of drag reduction for supersonic blunt body by pulse energy deposition

Shinichi Taguchi, Naofumi Ohnishi, Michiko Furudate, Keisuke Sawada

Collection of Technical Papers - 45th AIAA Aerospace Sciences Meeting　21　14760-14767　2007
Implicit les of compressible turbulent flow

Keiichi Ishiko, Naofumi Ohnishi, Keisuke Sawada

Collection of Technical Papers - 45th AIAA Aerospace Sciences Meeting　16　11154-11162　2007
Publisher: American Institute of Aeronautics and Astronautics Inc.
DOI： 10.2514/6.2007-920 　
Numerical analysis of plasma medium of a fully coherent x-ray laser Peer-reviewed

N. Ohnishi, M. Nishikino, A. Sasaki

X-RAY LASERS 2006, PROCEEDINGS　115　335-+　2007

ISSN： 0930-8989
Gravitational radiation from standing accretion shock instability in core-collapse supernovae Peer-reviewed

Kei Kotake, Naofumi Ohnishi, Shoichi Yamada

ASTROPHYSICAL JOURNAL　655　(1)　406-415　2007/01

DOI： 10.1086/509320 　

ISSN： 0004-637X
Numerical simulation of radiative heating environment on test case 6

Hiroshi Osawa, Yousuke Ogino, Kenichi Sugai, Naofumi Ohnishi, Keisuke Sawada

European Space Agency, (Special Publication) ESA SP　629　2006/11

ISSN： 0379-6566
Multiband radiation model for simulation of Galileo probe entry flowfield Peer-reviewed

Shingo Matsuyama, Yuji Shimogonya, Naofumi Ohnishi, Akihiro Sasoh, Keisuke Sawada

JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER　20　(3)　611-614　2006/07

DOI： 10.2514/1.16432 　

ISSN： 0887-8722
Numerical analysis of plasma medium of transient collisional excited X-ray laser Peer-reviewed

N. Ohnishi, M. Nishikino, A. Sasaki

JOURNAL DE PHYSIQUE IV　133　1193-1195　2006/06

DOI： 10.1051/jp4:2006133244 　

ISSN： 1155-4339
Numerical analysis of standing accretion shock instability with neutrino heating in supernova cores Peer-reviewed

N Ohnishi, K Kotake, S Yamada

ASTROPHYSICAL JOURNAL　641　(2)　1018-1028　2006/04

DOI： 10.1086/500554 　

ISSN： 0004-637X
Implicit les for two-dimensional turbulence using shock capturing monotone scheme

Keiichi Ishiko, Naofumi Ohnishi, Keisuke Sawada

Collection of Technical Papers - 44th AIAA Aerospace Sciences Meeting　12　8441-8452　2006
Publisher: American Institute of Aeronautics and Astronautics Inc.
DOI： 10.2514/6.2006-703 　
Comparative computation of radiative heating environment for huygens probe entry flight

Hiroshi Osawa, Shingo Matsuyama, Naofumi Ohnishi, Keisuke Sawada

Collection of Technical Papers - 9th AIAA/ASME Joint Thermophysics and Heat Transfer Conference Proceedings　4　2299-2309　2006
Numerical simulation of laser-driven in-tube accelerator operation Peer-reviewed

N. Ohnishi, Y. Ogino, K. Sawada, T. Ohtani, K. Mori, A. Sasoh

BEAMED ENERGY PROPULSION　830　191-+　2006

ISSN： 0094-243X
Physical processes of the interaction between laser-generated plasma and blast wave appearing in laser-driven in-tube accelerator configuration Peer-reviewed

Akihiro Sasoh, Koichi Mori, Toshiro Ohtani, Naofumi Ohnishi, Yosuke Ogino, Keisuke Sawada

BEAMED ENERGY PROPULSION　830　175-+　2006

ISSN： 0094-243X
Multigroup flux-limited diffusion neutrino transport simulations for magnetized and rotating core-collapse supernovae Peer-reviewed

Kei Kotake, Naofumi Ohnishi, Shoichi Yamada, Katsuhiko Sato

ORIGIN OF MATTER AND EVOLUTION OF GALAXIES　847　421-+　2006

ISSN： 0094-243X
Toward radiation-magnetohydrodynamic simulations in core-collapse supernovae Peer-reviewed

Kei Kotake, Naofumi Ohnishi, Shoichi Yamada, Katsuhiko Sato

THIRD 21COE SYMPOSIUM: ASTROPHYSICS AS INTERDISCIPLINARY SCIENCE　31　95-98　2006

DOI： 10.1088/1742-6596/31/1/015 　

ISSN： 1742-6588
Implicit LES of Turbulence Using Weighted Compact Scheme Peer-reviewed

Keiichi Ishiko, Naofumi Ohnishi, Keisuke Sawada

Nagare　24　(5)　515-523　2005/10
Publisher: The Japan Society of Fluid Mechanics
DOI： 10.11426/nagare1982.24.515 　

ISSN： 0286-3154

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Recently, Deng et al. have developed Weighted Compact Nonlinear Scheme, WCNS, that achieves high order spatial accuracy with less stencils. Because WCNS shows monotone shock capturing capability, we suppose the scheme is able to apply Implicit LES. In this study, Implicit LES of the Burgers turbulence using WCNS is carried out to obtain energy spectrum. It is found that the energy spectrum of Implicit LES using WCNS is in fair agreement with DNS whereas the result of LES shows non-physical bump in the highest wavenumber region.
Numerical attempts of capturing contact surface Peer-reviewed

K Sawada, N Ohnishi

NEW DEVELOPMENTS IN COMPUTATIONAL FLUID DYNAMICS　90　81-90　2005

ISSN： 1612-2909
Numerical simulation of Galileo probe entry flowfield with radiation and ablation Peer-reviewed

S Matsuyama, N Ohnishi, A Sasoh, K Sawado

JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER　19　(1)　28-35　2005/01

ISSN： 0887-8722
高Ｚ物質ドープによるレーザー核融合ターゲット表面でのレイリー・テイラー不安定性の抑制 Invited Peer-reviewed

藤岡慎介, 砂原淳, 大西直文, 疇地宏, 白神宏之, 中井光男, 重森啓介, 村上匡且, 長井圭治, 西村博明, 乗松孝好, 西原功修, 井澤靖和, 野崎真也, 陳延偉

プラズマ・核融合学会誌　80　(7)　597-604　2004/07
Publisher: The Japan Society of Plasma Science and Nuclear Fusion Research
DOI： 10.1585/jspf.80.597 　

ISSN： 0918-7928

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A scheme to suppress the ablative Rayleigh-Taylor (RT) instability using high-Z doped plastic target (brominated polystyrene;CHBr) has been proposed for a directly laser-driven IFE target. When an intense laser irradiates directly onto a high-Z doped target, radiation emitted from a corona plasma propagates and deposits locally its energy inside the target. The enhanced radiation forms the double-ablation structure, which consists of primaryelectron conduction ablation front and secondary radiative ablation front. The radiative ablation in the double-ablation structure has many advantages to suppress the growth of the RT instability in analogy of the indirect-drive approach, i.e. large mass ablation rate, long density scale length and low peak density. Two-dimensional (2D) hydrodynamic simulation code shows strong suppression of the RT instability in a brominated plastic (CHBr) target compared with that in an undoped polystyrene (CH) target. RT growth rates evaluated theoretically using the Betti-Goncharov procedure with one-dimensional(1D) radiation-hydrodynamic simulation are in good agreement with 2D simulation results. Several experiments were performed at the GEKKO XII- HIPER (High Intensity Plasma Experimental Research) laser facility. A trajectory of a laser-driven CHBr target observed in experiment was reproduced fairly well by 1D simulation code. The double-ablation structure formed inside a directly laser-driven CHBr target was clearly observed in experiments for the first time The strong suppression of the RT instability in the CHBr target was confirmed in experiments with face-on and side-on x-ray backlighting technique.
Suppression of the Rayleigh-Taylor instability due to self-radiation in a multiablation target Peer-reviewed

S Fujioka, A Sunahara, K Nishihara, N Ohnishi, T Johzaki, H Shiraga, K Shigemori, M Nakai, T Ikegawa, M Murakami, K Nagai, T Norimatsu, H Azechi, T Yamanaka

PHYSICAL REVIEW LETTERS　92　(19)　195001　2004/05

DOI： 10.1103/PhysRevLett.92.195001 　

ISSN： 0031-9007
Suppression of Rayleigh-Taylor instability due to radiative ablation in brominated plastic targets Invited Peer-reviewed

S Fujioka, A Sunahara, N Ohnishi, Y Tamari, K Nishihara, H Azechi, H Shiraga, M Nakai, K Shigemori, T Sakaiya, M Tanaka, K Otani, K Okuno, T Watari, T Yamada, M Murakami, K Nagai, T Norimatsu, Y Izawa, S Nozaki, YW Chen

PHYSICS OF PLASMAS　11　(5)　2814-2822　2004/05

DOI： 10.1063/1.1705654 　

ISSN： 1070-664X
Numerical attempt for capturing wing wake flows

Keisuke Sawada, Naofumi Ohnishi

AIAA Paper　6786-6793　2004
Rayleigh-taylor instability and its reduction in laser-accelerated targets Peer-reviewed

Shiraga H, Shigemori K, Nakai M, Sakaiya T, Fujioka S, Tamari Y, Azechi H, Nishihara K, Sunahara A, Nagatomo H, Ikegawa T, Ohnishi N, Nagai K, Norimats T, Yamanaka T

Inertial Fusion Sciences and Applications 2003　115-120　2004
Two-dimensional hydrodynamic simulation of an accretion flow with radiative cooling in a close binary system Peer-reviewed

J Sato, K Sawada, N Ohnishi

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY　342　(2)　593-600　2003/06

DOI： 10.1046/j.1365-8711.2003.06574.x 　

ISSN： 0035-8711
Comparative study of contact surface capturing schemes

Keisuke Sawada, Naofumi Ohnishi, Hayato Baba, Hideo Nagatomo

16th AIAA Computational Fluid Dynamics Conference　2003
Publisher: American Institute of Aeronautics and Astronautics Inc.
DOI： 10.2514/6.2003-4117 　
Trajectory-based heating analysis of galileo probe entry flowfield with radiation and ablation

Shingo Matsuyama, Naofumi Ohnishi, Akihiro Sasoh, Keisuke Sawada

36th AIAA Thermophysics Conference　2003
Numerical simulation of non-spherical implosion related to fast ignition Peer-reviewed

H Nagatomo, N Ohnishi, K Mima, K Nishihara, S Yamada, K Sawada, H Takabe

PLASMA PHYSICS　669　253-256　2003

ISSN： 0094-243X
Distributed-memory parallelization of radiative transfer calculation in hypersonic flow Peer-reviewed

S Matsuyama, N Ohnishi, A Sasoh, K Sawada

PARALLEL COMPUTATIONAL FLUID DYNAMICS: NEW FRONTIERS AND MULTI-DISCIPLINARY APPLICATIONS, PROCEEDINGS　491-498　2003

DOI： 10.1016/B978-044450680-1/50062-0 　
Imprint reduction in a plasma layer preformed with x-ray irradiation Peer-reviewed

M Nishikino, H Shiraga, N Miyanaga, N Ohnishi, K Shigemori, S Fujioka, M Nakai, H Nishimura, H Azechi, K Mima, H Takabe, S Nakai, T Yamanaka

PHYSICS OF PLASMAS　9　(4)　1381-1391　2002/04

DOI： 10.1063/1.1455629 　

ISSN： 1070-664X
Radiation effects on hydrodynamic perturbation growth due to non-uniform laser irradiation Peer-reviewed

N Ohnishi, H Nagatomo, H Nishimura, H Takabe, T Yamanaka

JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER　71　(2-6)　551-560　2001/10

DOI： 10.1016/S0022-4073(01)00097-8 　

ISSN： 0022-4073

eISSN： 1879-1352
Radiation roles on reduction of initial imprint in foam-buffered targets Peer-reviewed

N. Ohnishi, H. Nagatomo, H. Nishimura, H. Takabe, T. Yamanaka

J. Plasma Fusion Res.　77　(10)　1018-1026　2001/10
Publisher:
ISSN： 0918-7928

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The initial imprint of mass perturbation on a target due to the spatial nonuniformity of laser intensity is a critical issue for laser fusion research. A foam-hybrid target with a low-density foam layer, and that was coated with high-Z material, was proposed to mitigate the laser imprint. In such a target, x-ray radiation played significant roles in the formation of the initial imprint. The perturbation in the absorbed laser energy is diffused by the radiation transport. For short wavelengths, a clear suppression of the perturbation growth was observed in the foam-hybrid target, although the growth rate of Rayleigh-Taylor instability was almost the same as that observed in conventional plastic targets. Hydrodynamic instability at the interface of the material was also suppressed with high-Z coating. Good agreement between the numerical results and the experimental findings suggests the validity of radiation hydrodynamic modeling.
Enhancement of thermal smoothing effect on laser imprint with soft X-ray radiation Peer-reviewed

N Ohnishi, H Nagatomo, H Takabe, H Nishimura, M Nishikino, H Shiraga, T Yamanaka

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS　40　(3A)　1435-1442　2001/03

DOI： 10.1143/JJAP.40.1435 　

ISSN： 0021-4922
Indirect-direct hybrid target experiments with the GEKKO XII laser Peer-reviewed

H Nishimura, H Shiraga, H Azechi, N Miyanaga, M Nakai, N Izumi, M Nishikino, M Heya, K Fujita, Y Ochi, K Shigemori, N Ohnishi, M Murakami, K Nishihara, R Ishizaki, H Takabe, K Nagai, T Norimatsu, M Nakatsuka, T Yamanaka, S Nakai, C Yamanaka, K Mima

NUCLEAR FUSION　40　(3Y)　547-556　2000/03

DOI： 10.1088/0029-5515/40/3Y/315 　

ISSN： 0029-5515
Computational study of x-ray radiation effects on hydrodynamic instability Peer-reviewed

N Ohnishi, H Nagatomo, H Takabe, H Nishimura, M Nishikino, H Shiraga, T Yamanaka

HIGH-POWER LASERS IN ENERGY ENGINEERING　3886　473-480　2000

ISSN： 0277-786X
Numerical analysis of imprint mitigation with soft x-ray radiation using integrated code Peer-reviewed

N. Ohnishi, H. Nagatomo, H. Takabe, H. Nishimura, M. Nishikino, H. Shiraga, T. Yamanaka

Inertial Fusion Sciences and Applications 99　184-187　2000
Nonlinear theory of laser imprint, Richtmyer-Meshkov and Rayleigh-Taylor instabilities Peer-reviewed

K. Nishihara, M. Murakami, N. Ohnishi, T. Ikegawa, Y. Fukuda, A. Sunahara, H. Nagatomo, H. Takabe, K. Mima

Proceedings of the 18th IAEA Fusion Energy Conference　IFP/16　2000
Recent progress of an integrated implosion code and modeling of element physics Peer-reviewed

H. Nagatomo, H. Takabe, K. Mima, N. Ohnishi, A. Sunahara, T. Takeda, K. Nishihara, A. Nishiguchi, K. Sawada

Proceedings of the 18th IAEA Fusion Energy Conference　IFP/20　2000
Recent studies of laser produced plasmas Peer-reviewed

H Takabe, H Nagatomo, A Sunahara, N Ohnishi, AI Mahdy, Y Yoda, S Naruo, H Azechi, H Nishimura, K Mima

PLASMA PHYSICS AND CONTROLLED FUSION　41　A75-A97　1999/03

DOI： 10.1088/0741-3335/41/3A/005 　

ISSN： 0741-3335
Target design for ignition and high gain in direct drive ICF Peer-reviewed

H Takabe, H Nagatomo, A Sunahara, N Ohnishi, S Kato, AI Mahdy, H Azechi, K Mima

FUSION ENGINEERING AND DESIGN　44　105-110　1999/02

DOI： 10.1016/S0920-3796(98)00363-9 　

ISSN： 0920-3796
Further development of integrated implosion code based on ILESTA-2D Peer-reviewed

H Nagatomo, H Takabe, N Ohnishi, S Kato, K Mima

FUSION ENGINEERING AND DESIGN　44　187-190　1999/02

DOI： 10.1016/S0920-3796(98)00333-0 　

ISSN： 0920-3796

eISSN： 1873-7196
Laser fusion and laboratory astrophysics with intense lasers Peer-reviewed

H Takabe, H Nagatomo, A Sunahara, N Ohnishi, Y Yoda, AI Mahdy, K Mima

NUMERICAL ASTROPHYSICS　240　423-426　1999
Integrated code development and analysis of implosion and hydrodynamic experiments Peer-reviewed

H. Takabe, H. Nagatomo, H. Azechi, K. Fujita, M. Murakami, S. Naruo, K. Nishihara, H. Nishimura, N. Ohnishi, Y. Ochi, Y. Sentoku, K. Shigemori, A. Sunahara, A. I. Mahdy, K. Mima

Fusion Energy 1998　3　1115　1999

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Misc. 151

Experiments of generation of collisionless shocks propagating into magnetized plasma

山崎了, 田中周太, 相原研人, 佐藤雄飛, 塩田珠里, 高田敦也, 松井啓一郎, 佐野孝好, 太田雅人, 江頭俊輔, 倉本織羽乃, 松本雄志郎, 蔵満康浩, 南卓海, 境健太郎, 西本貴博, 岩崎滉, 松清修一, 森田太智, 松尾涼人, 児島拓仁, 枝本雅史, 富田健太郎, 竹崎太智, 小口拓哉, 星野真弘, 大平豊, 梅田隆行, 石井彩子, 大西直文, 冨田沙羅, 坂和洋一

衝撃波シンポジウム講演論文集(CD-ROM)　2021　2022
磁化プラズマ中を伝播する低マッハ数の無衝突衝撃波の生成実験

山崎了, 冨谷聡志, 遠田裕史, 宮田親, 安部大晟, 石坂夏規, 角地真, 瀬井柊人, 冨田沙羅, 坂和洋一, 佐野孝好, 江頭俊輔, 太田雅人, KUMAR Rajesh, 蔵満康浩, 松清修一, 森田太智, 富田健太郎, 枝本雅史, 小沼杏奈, 浅井晴貴, 飯田浩祐, 米田仁紀, 田中周太, 大西直文, 井上剛志, 梅田隆行, 高部英明, 星野真弘, 大平豊, 石井彩子, 寺木悠人

大阪大学レーザー科学研究所共同利用・共同研究成果報告書(CD-ROM)　2017　ROMBUNNO.1‐1　2018/03
大気圏突入流れ場における励起種の非平衡数値計算

荻野要介, 大西直文

第62回宇宙科学技術連合講演会講演論文集　2018
空気分子励起種を含む極超音速流計算と輻射輸送解析

荻野要介, 大西直文

第50回流体力学講演会/第36回航空宇宙数値シミュレーション技術シンポジウム講演論文集　2018
励起化学種を考慮した非平衡衝撃波解析と輻射熱輸送計算

荻野要介, 大西直文

平成29年度衝撃波シンポジウム講演論文集　2018
磁化プラズマ中を伝播する低マッハ数の無衝突衝撃波の生成実験

山崎了, 正治圭崇, 冨谷聡志, 遠田裕史, 宮田親, 大平豊, 冨田沙羅, 小林瑛史, 野上雅弘, 木坂将大, 坂和洋一, 佐野孝好, KUMAR Rajesh, 下河原浩志, 松清修一, 森田太智, 富田健太郎, 香月のどか, 小沼杏奈, 米田仁紀, 田中周太, 大西直文, 石井彩子, 蔵満康浩, 梅田隆行, 高部英明, 星野真弘, 森高外征雄, 高峰愛子, 寺木悠人, 井上剛志

大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書　2016　9‐10　2017/03
衝突・輻射非平衡モデルを用いた極超音速流解析と輻射熱輸送計算

荻野要介, 大西直文, 丹野英幸

平成28年度衝撃波シンポジウム講演論文集　2017
高出力レーザーを用いたプラズマ中衝撃波における磁場増幅モデル実験とその解析 II

下河原浩志, 坂和洋一, RAJESH Kumar, 森田太智, 富田健太郎, 松清修一, 山崎了, 蔵満康浩, 佐野孝好, 大西直文, 水田晃, 高部英明, 森高外征雄

日本物理学会講演概要集(CD-ROM)　71　(2)　ROMBUNNO.16aKC‐4-704　2016/09/23
Publisher: The Physical Society of Japan
DOI： 10.11316/jpsgaiyo.71.2.0_704 　

ISSN： 2189-079X
大型レーザー生成プラズマ中衝撃波における磁場増幅のモデル実験

下河原浩志, 坂和洋一, 原由紀子, KUMAR Rajesh, 森田太智, 富田健太郎, 松清修一, 山崎了, 蔵満康浩, 森高外征雄, 佐野孝好, 大西直文, 水田晃, 高部英明

日本物理学会講演概要集(CD-ROM)　71　(1)　ROMBUNNO.22AAE‐12　2016/03/22

ISSN： 2189-079X
磁化プラズマ中を伝播する低マッハ数の無衝突衝撃波の生成実験

山崎了, 正治圭崇, 冨谷聡志, 冨田沙羅, 大平豊, 坂和洋一, 佐野孝好, 原由希子, 下河原浩志, 松清修一, 森田太智, 富田健太郎, 米田仁紀, 蔵満康浩, 森高外征雄, 大西直文, 石井彩子, 梅田隆行, 高部英明, 田中周太, 寺木悠人, 井上剛志

大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書　2015　26-27　2016/03
衝突輻射過程を考慮した空気プラズマ流と輻射熱輸送の計算

荻野要介, 大西直文, 丹野英幸

第30回数値流体力学シンポジウム講演論文集　2016
Numerical Study on Heat Flux Augmentation by Forced Turbulence in Hypersonic Flow

59　4p　2015/10/07
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
Numerical analysis of radiative heating on a reentry capsule using collisional-radiative model

59　6p　2015/10/07
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
Numerical Study of Microwave Rocket for Improvement of Thrust Performance

59　5p　2015/10/07
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
Two-dimensional PIC Simulation of Plasma Thruster with Rotating Magnetic Field

59　3p　2015/10/07
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
S0530103 Numerical Analysis of Pulse Discharge Process in DBD Plasma Actuator

SATO Shintaro, OHNISHI Naofumi

Mechanical Engineering Congress, Japan　2015　"S0530103-1"-"S0530103-5"　2015/09/13
Publisher: The Japan Society of Mechanical Engineers

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Dielectric barrier discharge (DBD) plasma actuator has been investigated for decades because of its advantages compared to existing flow-control devices. Periodic current pulses are observed when intermittent discharges occur by applying a time-varying voltage. We have conducted two-dimensional simulations of the DBD plasma actuator with a drift-diffusion model. The discharge regime can be classified into two phases. In the first phase, a positive ion cloud is formed at the edge of the exposed electrode due to electron avalanche. A simple theoretical model is proposed, which takes into account time evolution of electron number density at the edge of the exposed electrode using the first Townsend ionization coefficient and provides a good agreement with the result of the numerical simulation. In the second phase, the cloud expands along the dielectric surface, followed by the streamer propagation at a high velocity. The period of streamer discharge cycle becomes shorter as the voltage slope increases. The simulation result shows that the period of the first phase is inversely proportional to the voltage slope, while that of the second phase is inversely proportional to the square of the voltage slope.
S1910305 Computation of Turbulent Heat Flux over Reentry Capsule in Hypersonic Flow

Ishihara Tomoaki, Ogino Yousuke, Ohnishi Naofumi, Sawada Keisuke, Tanno Hideyuki

Mechanical Engineering Congress, Japan　2015　"S1910305-1"-"S1910305-5"　2015/09/13
Publisher: The Japan Society of Mechanical Engineers

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Aeroheating measurements on the heatshield of the 6.4% scaled Apollo capsule model and the backshell of 6% scaled HTV-R capsule with forced turbulent transition was performed at the higher enthalpy conditions in the free-piston shock tunnel HIEST of JAXA Kakuda Space Center. When the flowfield becomes turbulent behind the roughness, heat flux on the heatshield and backshell were 1.5-3 times larger than one in laminar flow. For the safe design of thermal protection system, the estimation of the maximum of the turbulent heat flux in high enthalpy condition by CFD is needed. We computed the flowfield by the forced transition using the Splart-Allmaras and Baldwin-Lomax model, and compared with the measured data. We could find that RANS resutls can obtain good agreement with the measure data in the low enthalpy conditions on the heatshield. On the other hand, the computed heat flux is larger than measured data in the high enthalpy conditions. However, the heat flux on the backshell depends on the height of the roughness and becomes smaller than measured data. This implies that the flowfield calculation around the various height of the roughness is needed.
磁化プラズマ中を伝播する低マッハ数の無衝突衝撃波の生成実験

山崎了, 正治圭崇, 河村有志郎, 冨田沙羅, 大平豊, 坂和洋一, 高部英明, 佐野孝好, 森高外征雄, 原由希子, 近藤さらな, 松清修一, 森田太智, 富田健太郎, 米田仁紀, 長嶺和慶, 蔵満康浩, 大西直文, 梅田隆行

大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書　2014　21-22　2015/03
超音速対向プラズマ流による無衝突衝撃波の生成

坂和洋一, 原由希子, 近藤さらな, 森田太智, 蔵満康浩, 佐野孝好, 森高外征雄, 西川和孝, 佐藤裕太, 富田健太郎, 内野喜一郎, 中野谷賢, 藤野亮佑, 久保聡一朗, 松清修一, 齋藤直哉, 正治圭崇, 河村有志郎, 冨田沙羅, 山崎了, 長峰和慶, 米田仁紀, 大西直文, ZHU Baojun, LI Yanfei, LI Yutong, PEI Xiaoxing, WEI Huigang, ZHONG J, CHU Hsu‐Hsin, CROWSTON R, WOOSLEY N, KOENIG M, BARROSO Patrice, MICHAUT C, ZHANG Z, 乗松孝好, 高部英明

大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書　2014　39-40　2015/03
Nonequilibrium Plasma Flow Computation with Atomic and Molecular State Transitions

Yousuke Ogino, Kosuke Totani, Naofumi Ohnishi

AIAA paper　(2015-0979)　1-9　2015
衝突・輻射モデルを用いた極超音速流れの数値計算

荻野要介, 戸谷晃輔, 大西直文

平成26年度衝撃波シンポジウム講演論文集　2015
極超音速流れ場における非平衡原子・分子過程解析コード開発

荻野要介, 戸谷晃輔, 大西直文

日本機械学会2015年度年次大会講演論文集　2015
Development of LES Code for Hypersonic Turbulent Flowfield Based on High Order WENO Scheme

Ishihara Tomoaki, Ogino Yousuke, Ohnishi Naofumi, Sawada Keisuke, Tanno Hideyuki

The Computational Mechanics Conference　2014　(27)　768-770　2014/11/22
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X

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An aeroheating measurement test campaign on an HTV-R capsule model with turbulent boundary layers was performed in the free-piston shock tunnel HIEST at JAXA Kakuda Space Center. When flow became turbulent flow, heat flux on rear body was 2-3 times larger than one in laminar flow. In order to reproduce the turbulent heat flux by numerical simulation, we constructed high order CFD code towards LES in hypersonic flow. Since robustness near shock and high resolution in boundary layer is needed for LES in hypersonic flow, we employed recently improved WENO method. We calculated the hypersonic flow (M_∞=17) around cylinder and investigated the robustness for strong shock by this method. We could obtain smooth pressure distribution and good agreement with the calculated heat flux by NASA LAURA code. The hypersonic flowfield around HTV-R was also calculated towards predicting turbulent heat flux on after body.
Numerical analysis of radiative heating in Earth re-entry using collisional-radiative model

58　5p　2014/11/12
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
Ionization Frequency Dependence of Atmospheric Plasma Formation by High-Power Microwave

58　4p　2014/11/12
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
S1910103 Computation of Forced Turbulent Flow over Reentry Capsule Afterbody with High Order Scheme

Ishihara Tomoaki, Ogino Yousuke, Ohnishi Naofumi, Sawada Keisuke, Tanno Hideyuki

Mechanical Engineering Congress, Japan　2014　"S1910103-1"-"S1910103-5"　2014/09/07
Publisher: The Japan Society of Mechanical Engineers

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An aeroheating measurement test campaign on an Apollo capsule model with turbulent boundary layers was performed in the free-piston shock tunnel HIEST at JAXA Kakuda Space Center. When flow became turbulent flow, heat flux on fore and rear body was 1.5-2 times larger than one in laminar flow. In order to reproduce the heat flux by numerical simulation, we constructed high order CFD code towards LES in hypersonic flow. Since robustness near shock and high resolution in boundary layer is needed for LES in hypersonic flow, we employed recently improved WENO method. We calculated the hypersonic flow (M_∞ = 17) around cylinder and investigated the robustness for strong shock by this method. We could obtain smooth pressure distribution and good agreement with the calculated heat flux by NASA LAURA code. The hypersonic flow field around HTV-R, which is a manned space capsule under development by JAXA was also calculated towards predicting heat flux on after body.
S1910102 Sensitivity Analysis of Thermochemical Nonequilibrium Model Based on Viscous Shock Layer Equation

KINO Takumi, OGINO Yousuke, OHNISHI Naofumi

Mechanical Engineering Congress, Japan　2014　"S1910102-1"-"S1910102-5"　2014/09/07
Publisher: The Japan Society of Mechanical Engineers

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To protect a spacecraft entering planetary atmosphere from severe aerodynamic heating, an appropriate thermal protection system must be designed by a sophisticated simulator which provides a precise prediction of heat load at the vehicle surface. In a hypersonic speed, highly nonequilibrium flow is formed at the front of the vehicle, and thus thermochemical modeling is crucial for predicting the aerodynamic heating. Although some models have been proposed by comparing flight data so far, we should know the uncertainty in the models for obtaining a high fidelity prediction of the hypersonic flow. In this study, we have investigated on uncertainty quantification and sensitivity analysis for the present and advanced thermochemical models. Since computational costs for the uncertainty quantification using conventional Monte-Carlo approach and full Navier-Stokes code are considerably expensive with number of uncertainty variables, we have performed the uncertainty quantification for the thermochemical models via non-intrusive polynomial chaos approach coupling with viscous shock-layer code, which works with much lower computational costs. In the analysis on O2 and N2 dissociations of the reentry flowfield, the stand-off distance of the detached shock wave is deviated by the uncertainty of the reaction rate constants especially for the nitrogen dissociation.
10aAK-7 Observation of femtosecond laser ablation process on Tungsten by using soft x-ray laser probe

Eyama T., Kakimoto N., Tomita T., Hasegawa N., Nishikino M., Minami Y., Baba M., Ohnishi N., Ito A. M., Kawachi T., Yamagiwa M., Suemoto T.

Meeting abstracts of the Physical Society of Japan　69　(2)　673-673　2014/08/22
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
27pAT-10 Assessment of implosion performances on high-Z doped ICF target

Shiroto Takashi, Ohnishi Naofumi, Sunahara Atsushi, Fujioka Shinsuke

Meeting abstracts of the Physical Society of Japan　69　(1)　240-240　2014/03/05
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
27aAX-2 Observation of the femto-second laser ablation dynamics of metals by using soft x-ray probe (II)

Nishikino M., Hasegawa N., Tomita T., Eyama T., Kakimoto N., Ohnishi N., Hatomi D., Ito A. M., Minami Y., Takei R., Baba M., Kawachi T., Yamagiwa M., Suemoto T.

Meeting abstracts of the Physical Society of Japan　69　(1)　232-232　2014/03/05
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
27aAX-1 Observation of the femto-second laser ablation dynamics of metals by using the soft x-ray probe (I)

Hasegawa N., Nishikino M., Tomita T., Eyama T., Kakimoto N., Hatomi D., Ohnishi N., Ito A. M., Minami Y., Takei R., Baba M., Kawachi T., Yamagiwa M., Suemoto T.

Meeting abstracts of the Physical Society of Japan　69　(1)　232-232　2014/03/05
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
27pCK-9 Observation of the laser ablation dynamics on metal surfaces by using soft x-ray imaging

Tomita T., Eyama T., Kakimoto N, Hasegawa N, Nishikino M., Minami Y., Takei R., Baba M., Ohnishi N., Hatomi D., Kaihori T., Morita T., Hirano Y., Kawachi T., Yamagiwa M., Suemoto T.

Meeting abstracts of the Physical Society of Japan　69　(1)　740-740　2014/03/05
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
28aAP-3 Observation of femto-second laser ablation process of metal by using the shadow graph and soft X-ray Newton ring

Eyama T., Kakimoto N., Tomita T., Hasegawa N., Nishikino M., Minami Y., Takei R., Baba M., Hatomi D., Ohnishi N., Kaihori T., Morita T., Hirano Y., Kawachi T., Yamagiwa M., Suemoto T.

Meeting abstracts of the Physical Society of Japan　69　(1)　875-875　2014/03/05
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
28aAP-2 Observation of the femto-second laser ablation dynamics of metals by using the soft x-ray laser probe

Yamagiwa M., Hasegawa N., Nishikino M., Tomita T., Eyama T., Kakimoto N., Hatomi D., Ohnishi N., Ito A. M., Minami Y., Takei R., Baba M., Kawachi T., Suemoto T.

Meeting abstracts of the Physical Society of Japan　69　(1)　874-874　2014/03/05
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
28aAP-4 Molecular Dynamics Analysis of Ablation Processes on Metal Surface by Femtosecond Laser Irradiation

Hatomi D., Ohnishi N., Nishikino M., Hasegawa N., Tomita T., Ito A. M., Kawachi T., Yamagiwa M., Suemoto T.

Meeting abstracts of the Physical Society of Japan　69　(1)　875-875　2014/03/05
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
高出力レーザー生成無衝突衝撃波のトムソン散乱計測

坂和洋一, 山浦裕太, 森田太智, 石川大志, 和田垣智也, 佐野孝好, 森高外征雄, ZHANG Z, 佐藤裕太, 下田諒, 富田健太郎, 内野喜一郎, 諌山翔伍, 藤野亮佑, 大山達也, 原田大輔, 松清修一, 長峰和慶, 米田仁紀, 大西直文, 水田晃, YUAN D., LI Y, ZHANG K, ZHONG J, CROWSTON R, WOOLSEY N, PELKA A, KOENIG M, YURCHAK R, MICHAUT C, BARROSO P, 蔵満康浩, 高部英明

日本物理学会講演概要集　69　(1)　272-272　2014/03/05
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
実験室宇宙プラズマの輻射流体シミュレーション

大西直文, 石井彩子, 水田晃, 蔵満康浩, 森田太智, 坂和洋一, 高部英明

大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書　2013　245-246　2014/03
超音速対向プラズマ流による無衝突衝撃波の生成

坂和洋一, 森田太智, 山浦裕太, 石川大志, 和田垣智也, 蔵満康浩, 佐野孝好, 森高外征雄, 下田諒, 佐藤裕太, 富田健太郎, 内野喜一郎, 諌山翔伍, 藤野亮佑, 大山達也, 原田大輔, 松清修一, 長峰和慶, 米田仁紀, 大西直文, 水田晃, ZHANG Z, 乗松孝好, YIN C, YUAN D., LI Y, ZHANG K, ZHONG J, CROWSTON R, WOOLSEY N, PELKA A, YURCHAK R, KOENIG M, BOUDENNE J, MICHAUT C, 高部英明

大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書　2013　27-28　2014/03
原子・分子過程を考慮した空気プラズマ流計算コードの開発

荻野要介, 戸谷晃輔, 大西直文

第46回流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム2014講演論文集　2014
Trajectory and Thermal Analyses for Disk-shaped Dust Particles in a Shock Layer

57　6p　2013/10/09
Publisher: 日本航空宇宙学会
ISSN： 1884-1945
S052021 Hybrid Simulation of Dielectric Barrier Discharge and Induced Flow

OHNISHI Naofumi, SUGIMOTO Kazuya, TAKAHASHI Masayuki

Mechanical Engineering Congress, Japan　2013　"S052021-1"-"S052021-4"　2013/09/08
Publisher: The Japan Society of Mechanical Engineers

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Modeling of minute plasma formation is of great importance around electrodes of a plasma actuator(PA) utilizing dielectric barrier discharge(DBD)with a relatively low computational cost. Although electrons need some distance to acquire sufficient energy causing impact ionization, such a transient phenomenon cannot be described in a conventional fluid model because of local field approximation. In order to simulate appropriate discharge process in the DBD-PA, a hybrid code coupling with a particle model was constructed, which treats high-density region as the fluid model but high electric field region as the particle model. The hybrid simulation reproduced spreading of the high-density region from the exposed electrode for the positively biased case as well as the full-particle simulation.
Results of laser experiments for collisionless shocks

Sakawa Y., Kuramitsu Y., Morita T., Yamaura Y., Ishikawa T., Sano Y., Moritaka T., Inoue K., Shimoda R., Tomita K., Uchino K., Nagamine K., Yoneda H., Matsukiyo S., Onishi N., Mizuta A., Norimatsu T., Nishida A., Kodama, Yuan D., Li Y., Zhang K., Wang F., Zhong J., Crowston R., Woolsey N., Doyle H., Gregori G., Pelka A., Koenig M., Boudenne J., Michaut C., Spitkovsky A., Kugland N.L., Ross J.S., Park H.-S., Remington B., Takabe H.

Meeting abstracts of the Physical Society of Japan　68　(2)　202-202　2013/08/26
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Numerical analysis of perturbation growth on lightly brominated plastic targets

SHIROTO Takashi, OHNISHI Naofumi, SUNAHARA Atsushi, FUJIOKA Shinsuke

Meeting abstracts of the Physical Society of Japan　68　(2)　187-187　2013/08/26
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Observation of the femto-second laser ablation dynamics of metals in the time scale of picosecond to sub-microsecond.

Hasegawa A., Tomita T., Nishikino M., Minami Y., Baba M., Takei R., Eyama T., Kakimoto N., Hatomi D., Ohnishi N., Kaihori T., Hirano Y., Morita T., Kawachi T., Yamagiwa M., Suemoto T.

Meeting abstracts of the Physical Society of Japan　68　(2)　827-827　2013/08/26
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Molecular Dynamics Simulation of Femtosecond Laser Abration Processes on Pt Surface

Hatomi Daiki, Ohnishi Naofumi, Nishikino Masaharu, Hasegawa Noboru, Tomita Takuro, Kawachi Tetsuya, Yamagiwa Minoru, Suemoto Tohru

Meeting abstracts of the Physical Society of Japan　68　(2)　828-828　2013/08/26
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
高出力レーザー生成プラズマ及び衝撃波のターゲット材質依存性について

山浦佑太, 坂和洋一, 蔵満康浩, 森田太智, 石川大志, 森高外征雄, 佐野孝好, 下田亮, 富田健太郎, 内野喜一郎, 松清修一, 水田晃, 大西直文, CROWSTON R, WOOLSEY N, DOYLE H, GREGORI G, RAVASIO A, PELKA A, KOENIG M, MICHAUT C, YUAN D., LI Y, ZHANG K, ZHONG J, WANG F, 高部英明

日本物理学会講演概要集　68　(2)　211-211　2013/08/26
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
無衝突衝撃波のレーザー模擬実験の成果

坂和洋一, 蔵満康浩, 森田太智, 山浦裕太, 石川大志, 佐野孝好, 森高外征雄, 井上和哉, 下田諒, 富田健太郎, 内野喜一郎, 長峰和慶, 米田仁紀, 松清修一, 大西直文, 水田晃, 乗松孝好, 西田明憲, 兒玉了祐, YUAN D., LI Y, ZHANG K, WANG F, ZHONG J, CROWSTON R, WOOLSEY N, DOYLE H, GREGORI G, PELKA A, KOENIG M, BOUDENNE J, MICHAUT C, SPITKOVSKY A, KUGLAND N.L, ROSS J.S, PARK H.‐S, REMINGTON B, 高部英明

日本物理学会講演概要集　68　(2)　121　2013/08/26

ISSN： 1342-8349
高出力レーザーを用いたプラズマジェットのコリメーション現象の研究

石川大志, 坂和洋一, 蔵満康浩, 森田太智, 山浦祐太, 森高外征雄, 佐藤孝好, 下田亮, 富田健太郎, 内野喜一郎, 松清修一, 水田晃, 大西直文, CROWSTON R, WOOLSEY N, DOYLC H, GREGORI G, RAVASIO A, PELKA A, KOENIG M, MICHAUT C, YUAN D., LI Y, ZHANG K, ZHONG J, WANG F, 高部英明

日本物理学会講演概要集　68　(2)　211-211　2013/08/26
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
29pEA-1 Experimental study on high Mach number collisionless shocks

Kuramitsu Y., Sakawa Y., Morita T., Moritaka T., Sano T., Tomita K., Uchino K., Matsukiyo S., Mizuta A., Ohnishi N., Takabe H.

Meeting abstracts of the Physical Society of Japan　68　(1)　307-307　2013/03/26
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
高マッハ数無衝突衝撃波の実験的研究

蔵満康浩, 坂和洋一, 森田太智, 森高外征雄, 佐野孝好, 富田健太郎, 内野喜一郎, 松清修一, 水田晃, 大西直文, 高部英明

日本物理学会講演概要集　68　(1)　307　2013/03/05

ISSN： 1342-8349
実験室宇宙プラズマの輻射流体シミュレーション

大西直文, 木下詩織, 水田晃, 蔵満康浩, 森田太智, 坂和洋一, 高部英明

大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書　2012　265-266　2013/03
高出力レーザーによって生成された高速対向プラズマ流による無衝突衝撃波の生成

坂和洋一, 蔵満康浩, 森田太智, 山浦裕太, 石川大志, 佐野孝好, 森高外征雄, 井上和哉, 下田諒, 富田健太郎, 内野喜一郎, 長峰和慶, 米田仁紀, 松清修一, 大西直文, 水田晃, 乗松孝好, 西田明憲, 兒玉了祐, YUAN D., LI Y, ZHANG K, WANG F, ZHONG J, CROWSTON R, WOOSLEY N, DOYLE H, GREGORI G, PELKA A, KOENIG M, BOUDENNE J, MICHAUT C, 高部英明

大阪大学レーザーエネルギー学研究センター共同利用・共同研究成果報告書　2012　24-25　2013/03
レーザーによる実験室宇宙物理:無衝突衝撃波に伴う電磁場乱流

蔵満康浩, 坂和洋一, 森田太智, 森高外征雄, 佐野孝好, 松本洋介, 水田晃, 大西直文, 高部英明

レーザー研究　41　(1)　20-24　2013/01
Publisher: レーザー学会
ISSN： 0387-0200
S056012 Hybrid Simulation of Discharge Structure Transition in DBD Plasma Actuator

SUGIMOTO Kazuya, OHNISHI Naofumi

Mechanical Engineering Congress, Japan　2012　"S056012-1"-"S056012-4"　2012/09/09
Publisher: The Japan Society of Mechanical Engineers

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We have developed a hybrid model based on particle and fluid approaches to study process of flow generation in a dielectric barrier discharge (DBD) plasma actuator. Two-dimensional simulations were conducted by this code with a constant applied voltage. In the case with a positively biased exposed electrode against covered electrode, ion cloud is generated on the exposed electrode and spreads to the downstream followed by high-density plasma. Since the obtained result is similar to the pure particle simulation, our hybrid model is reasonable to describe dynamics of the dielectric barrier discharge. A plasma simulation over wide range with a low-cost computation is expected using the developed code and must help us further understanding of thrust generation process of the DBD plasma actuator.
Fundamentals of Radiation Hydrodynamics Simulation

OHNISHI Naofumi

プラズマ・核融合学会誌　88　(9)　2012/09
Publisher: プラズマ・核融合学会
20aFC-14 Effect of distance between two ablation fronts on high-Z doped plastic targets

SHIROTO Takashi, OHNISHI Naofumi, SUNAHARA Atsushi, FUJIOKA Shinsuke

Meeting abstracts of the Physical Society of Japan　67　(2)　213-213　2012/08/24
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Computational Code for Air Plasma Flowfield with Atomic and Molecular Processes

Yousuke Ogino, Tomoaki Ishihara, Atsushi Nagano, Naofumi Ohnishi

AIAA Paper　2012
衝突輻射モデルによる高エンタルピー流解析コードの開発

荻野要介, 石原知明, 大西直文

日本流体力学会年会2012講演論文集　2012
Code Development of Atmospheric Reentry Flow with Atomic and Molecular Processes

Yousuke Ogino, Tomoaki Ishihara, Naofumi Ohnishi, Keisuke Sawada

ESA Publications Division　ESA SP-714　2012
Collisionless shock experiments using high-power laser systems

坂和洋一, 蔵満康浩, 森田太智, 丹治浩樹, 井出尭夫, 西尾健斗, 桑田三沙, 坪内邦男, 井手張良, 嶋崎成一, 田口俊弘, 加藤恒彦, 大西直文, 水田晃, 佐野孝好, 乗松孝好, 尾崎典雅, 兒玉了祐, 西田明憲, 並木智紀, 米田仁紀, 中山和貴, 富田健太郎, 内野喜一郎, WANG S., DONG Q., LI Y., GREGORY C., WOOLSEY N., SCHAAR K., MURPHY C., GREGORY G., DIZIERE A., PE1LKA A., KOENIG M., PARK H., ROSS S., KUGLAND N., RYUTOV D., REMINGTON B., SPITKOVSKY A., FROULA D., 高部英明

プラズマ・核融合学会年会(Web)　28th　2011
Numerical Study on Air Plasma Flow with Transition Rate Equations

Yousuke OGINO, Naofumi OHNISHI

AIAA paper　(2011-3622)　2011
22pEJ-6 Numerical simulation of spherical shock instability for core collapse supernovae

Nakano Wakana, Ohnishi Naofumi, Kotake Kei, Yamada Shoichi, Sawada Keisuke

Meeting abstracts of the Physical Society of Japan　65　(1)　338-338　2010/03/01
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
空気プラズマ流れ場の非平衡原子・分子過程解析コード開発

荻野要介, 江波戸翔一, 大西直文

プラズマ生成・電離過程に関わる突発性と構造形成研究会論文集　2010
Computational Model of Collisional-Radiative Nonequilibrium Plasma in an Air-Driven Type Laser Propulsion

Yousuke Ogino, Naofumi Ohnishi

AIP Conference Proceedings　1230　148-159　2010

DOI： 10.1063/1.3435431 　
Development of Computational Code for Atomic and Molecular Processes in High Enthalpy Flow

Yousuke Ogino, Naofumi Ohnishi

AIAA Paper　(2010-4308)　2010
気体駆動型レーザー推進における非平衡プラズマ流れ場計算

荻野要介, 大西直文, 澤田恵介

第54回宇宙科学技術連合講演会講演論文集　3C10　2010
原子・分子過程と空気プラズマ流の結合計算コード開発

荻野要介, 永野敦士, 大西直文, 澤田恵介

第24回数値流体力学シンポジウム講演論文集　E1-4　2010
定在降着衝撃波不安定性による中性子星キックの統計解析

岩上わかな, 山田章一, 固武慶, 大西直文, 澤田恵介

日本天文学会年会講演予稿集　2009　2009

ISSN： 1347-0639
Shock Control with Baroclinic Vortex Induced by a Pulse Energy Deposition

Yousuke Ogino, Masami Tate, Naofumi Ohnishi

AIAA Paper　(2009-1225)　2009
気体駆動型レーザー推進における衝突輻射非平衡プラズマ計算モデル

荻野要介, 大西直文

日本航空宇宙学会第40期年会講演会講演論文集　B08　2009
衝突輻射モデルによる非平衡空気プラズマ解析コードの開発

荻野要介, 大西直文

第53回宇宙科学技術連合講演会講演論文集　1L08　2009
空気プラズマ流れと原子・分子過程の計算コード開発

荻野要介, 楯真沙美, 大西直文

第23回数値流体力学シンポジウム講演論文集　E8-4　2009
26aQE-4 Numerical Analysis of Ablation Plasma with Computation of Anisotropic Radiation

Sugai Kenichi, Ohnishi Naofumi, Sunahara Atsushi

Meeting abstracts of the Physical Society of Japan　63　(1)　248-248　2008/02/29
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
26aQE-3 Radiation Hydrodynamic Simulations of Emission of Extreme Ultra-Violet Light and Dynamics of Laser-produced Tin Plasmas.

Sunahara A., Sugai K., Ohnishi N., Sasaki A., Ueda H., Nishihara K., Aota T., Fujioka S., Yamaura M., Shimada Y., Nishimura H., Miyanaga N., Izawa Y., Mima K.

Meeting abstracts of the Physical Society of Japan　63　(1)　248-248　2008/02/29
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Flow Simulation Around JAXA High-Lift Configuration Model Using High-Order Unstructured Method

芳賀臣紀, 大西直文, 澤田恵介, 増永晶久, 内山直樹

宇宙航空研究開発機構特別資料 JAXA-SP-　(07-016)　196-201　2008/02/29

ISSN： 1349-113X
重力崩壊型超新星コアにおける定在降着衝撃波不安定性に対する回転の効果

岩上わかな, 大西直文, 固武慶, 山田章一, 澤田恵介

日本天文学会年会講演予稿集　2008　2008

ISSN： 1347-0639
中性子星のキックやスピンに対する定在降着衝撃波の不安定性の影響

岩上わかな, 大西直文, 固武慶, 山田章一, 澤田恵介

日本天文学会年会講演予稿集　2008　2008

ISSN： 1347-0639
超新星爆発における球状降着衝撃波の不安定性の三次元数値解析

岩上わかな, 大西直文, 固武慶, 山田章一, 澤田恵介

第22回数値流体力学シンポジウム講演論文集　H3-4　2008
Three-dimensional analysis of spherical accretion shock instability for supernova explosion

Wakana Iwakami, Naofumi Ohnishi, Kei Kotake, Shoichi Yamada, Keisuke Sawada

第22回数値流体力学シンポジウム講演論文集　H3-4　2008
弧状衝撃波とブラスト波の干渉構造に関する数値的研究

荻野要介, 楯真沙美, 田口伸一, 大西直文, 澤田恵介

平成19年度衝撃波シンポジウム講演論文集　18-A-2-1　2008
Numerical Study on Blast Wave Propagation Driven by Unsteady Ionization Plasma

Yousuke Ogino, Naofumi Ohnishi, Keisuke Sawada

AIP Conference Proceedings　997　411-418　2008
高エンタルピー流における原子・分子過程解析コードの開発

荻野要介, 楯真沙美, 大西直文

第22回数値流体力学シンポジウム講演論文集　H2-2　2008
23pRS-7 Time-dependent spectroscopic measurements of helium- and lithium-like titanium ions in laser-produced underdense plasmas for X-ray generation

Iwamae A., Tanabe M., Fujioka S., Nishimura H., Nagai K., Ohnishi N., Frounier K. B., Girard F., Printout M., Viliette M., BREBION D., Tobin M., Mima K.

Meeting abstracts of the Physical Society of Japan　62　(2)　239-239　2007/08/21
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
23pRS-1 Supersonic propagation of heat-wave-front in laser plasma driven with low density target

Tanabe M., Nishimura H., Iwamae A., Fujioka S., Ohnishi N., Nagai K., Fournier K. B., Girard F., Primout M., Villette M., Babonneuau D., Tobin M., Mima K.

Meeting abstracts of the Physical Society of Japan　62　(2)　237-237　2007/08/21
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
重力崩壊型超新星コアで発生する停滞衝撃波の不安定性

岩上わかな, 大西直文, 固武慶, 山田章一

日本天文学会年会講演予稿集　2007　2007

ISSN： 1347-0639
Flow Simulation around JAXA High-Lift Configuration Model using High-Order Unstructured Method

芳賀臣紀, 大西直文, 澤田恵介, 増永晶久, 内山直樹

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　39th-2007　337-340　2007
Spectral volume computation of flowfield in aerospace application using earth simulator

Takanori Haga, Takanori Haga, Takanori Haga, Naofumi Ohnishi, Naofumi Ohnishi, Naofumi Ohnishi, Keisuke Sawada, Keisuke Sawada, Keisuke Sawada, Akihisa Masunaga, Akihisa Masunaga

Collection of Technical Papers - AIAA Applied Aerodynamics Conference　1　82-90　2006/12/18

ISSN： 1048-5953
30pUC-6 Collision Experiment of Super-High-Velocity Fluid for Impact Fast Ignition

Sakaiya T, Saito H, Otani K, Shiota T, Ichinose D, Shigemori K, Murakami M, Fujioka S, Nakai M, Shiraga H, Nagatomo H, Sunahara A, Ohnishi N, Azechi H, Mima K, Karasik M, Gardner J, Obenschain S, PHI- PDT- TM, GOD-group

Meeting abstracts of the Physical Society of Japan　61　(1)　245-245　2006/03/04
Publisher: 一般社団法人日本物理学会
ISSN： 1342-8349
Flow Simulation around JAXA High-Lift Configuration Model using High-Order Unstructured Method

芳賀臣紀, 大西直文, 澤田恵介, 増永晶久, 内山直樹

飛行機シンポジウム講演集(CD-ROM)　44th　2B12　2006
Numerical Analysis of Expanding Nonequilibrium Plasma in a Gas-Driven Laser Propulsion

Yousuke Ogino, Naofumi Ohnishi, Keisuke Sawada, Akihiro Sasoh

AIAA Paper　(2006-1358)　2006
レーザー生成プラズマの非平衡性とレーザー誘起ブラスト波の伝播

荻野要介, 大西直文, 佐宗章弘, 澤田恵介

日本航空宇宙学会北部支部2006年講演会論文集　U-9　2006
Blast Wave Formation by Laser-Sustained Nonequilibrium Plasma in the Laser-Driven In-Tube Accelerator Operation

Yousuke Ogino, Naofumi Ohnishi, Akihiro Sasoh, Keisuke Sawada

AIP Conference Proceedings　830　183-190　2006

DOI： 10.1063/1.2203261 　
Monodimensional Radiative Flowfield Simulation in Titan-like Atmosphere

Yousuke Ogino, Hiroshi Osawa, Naofumi Ohnishi, Keisuke Sawada

ESA Publications Division　ESA SP-629　82-87　2006
Nonequilibrium Blast Wave Simulation in a Gas-Driven Type Laser Propulsion

Yousuke Ogino, Naofumi Ohnishi, Akihiro Sasoh, Keisuke Sawada

3rd International Conference on Flow Dynamics Proceedings　211-212　2006
20aXK-13 Two-Dimensional Effect of Plasma Medium on the Gain of Transient Collisional Excited X-Ray Laser

Ohnishi Naofumi, Nishikino Masaharu, Sasaki Akira

Meeting abstracts of the Physical Society of Japan　60　(2)　107-107　2005/08/19
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
26pXB-14 Effect of Plasma Medium Distribution on Transient Collisional Excited X-Ray Laser

Ohnishi Naofumi, Nishikino Masaharu, Sasaki Akira

Meeting abstracts of the Physical Society of Japan　60　(1)　237-237　2005/03/04
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
自転磁場原始中性子星における非対称ニュートリノ放射

固武慶, 大西直文, 山田章一, 佐藤勝彦

日本天文学会年会講演予稿集　2005　2005

ISSN： 1347-0639
高次精度非構造Spectral Volume法の圧縮性非粘性流れ場への適用

芳賀臣紀, 大西直文, 澤田恵介

数値流体力学シンポジウム講演論文集(CD-ROM)　19th　A5-5　2005
レーザー駆動管内加速装置の非平衡輻射流れ場計算

荻野要介, 大西直文, 澤田恵介, 大谷俊朗, 佐宗章弘

日本航空宇宙学会第36期年会講演会講演論文集　35　2005
レーザー生成非平衡プラズマによるブラスト波の形成と伝播

荻野要介, 大西直文, 佐宗章弘, 澤田恵介

第19回数値流体力学シンポジウム講演論文集　D1-2　2005
24aB36P Observation of ablative Rayleigh-Taylor instability with laser-driven targets

Sakaiya T, Azechi H, Shigemori K, Nakai M, Shiraga H, Ohnishi N, Sunahara A, Nagatomo H, Izawa Y

プラズマ・核融合学会年会予稿集　(21)　166-166　2004/11/20
Publisher: The Japan Society of Plasma Science and Nuclear Fusion Research
Calculation of Unsteady Flowfield in Expansion Tube Using Contact Surface Resolving Technique

NAGATA Taku, OHNISHI Naofumi, SAWADA Keisuke

2004　(40)　95-96　2004/09/17
Publisher: The Japan Society of Mechanical Engineers
Implicit LES of Burgers Turbulence Using Weighted Compact Scheme

ISHIKO Keiichi, OHNISHI Naofumi, SAWADA Keisuke

2004　(40)　91-92　2004/09/17
Publisher: The Japan Society of Mechanical Engineers
28aWJ-2 Observation of Ablative Rayleigh-Taylor Instability at Medium Wavelength

Sakaiya T, Azechi H, Shigemori K, Nakai M, Shiraga H, Nagatomo H, Ohnishi N, Sunahara A, Izawa Y, PE1-group, MT-group, T-group, GO-group

Meeting abstracts of the Physical Society of Japan　59　(1)　222-222　2004/03/03
Publisher: 一般社団法人日本物理学会
ISSN： 1342-8349
28aWJ-3 ダブル・アブレーションを用いたレイリー・テイラー不安定性の抑制(核融合プラズマ(不安定性))(領域2)

藤岡慎介, 砂原淳, 大西直文, 疇地宏, 白神宏之, 中井光男, 重森啓介, 長井圭治, 乗松孝好, 井澤靖和, M

日本物理学会講演概要集　59　(1)　2004/03/03
Publisher: 一般社団法人日本物理学会
ISSN： 1342-8349
レーザー推進駆動気体における非局所熱非平衡輻射流れ場計算

荻野要介, 大西直文, 澤田恵介, 佐宗章弘

第18回数値流体力学シンポジウム講演論文集　E2-4　2004
Development of an Integrated Implosion Code based on CIP method for ICF

NAGATOMO Hideo, JOHZAKI Tomoyuki, SUNAHARA Atsushi, OHNISHI Naofumi, Mima Kunioki

The Computational Mechanics Conference　2003　(16)　223-224　2003/11/22
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
Formation of high-density core plasma for fast ignition

Nagatomo H., Johzaki T., Sunahara A., Ohnishi N., Mima K.

Meeting abstracts of the Physical Society of Japan　58　(2)　156-156　2003/08/15
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Reduction of Growth Rate of Ablative Rayleigh-Taylor Instability at Medium Wavelengths

Sakaiya T, Azechi H, Shiraga H, Nakai M, Shigemori K, Ohnishi N, Sunahara A, Nagatomo H, Nishihara K, Izawa Y, PE, MT-, T, GO-group

Meeting abstracts of the Physical Society of Japan　58　(2)　162-162　2003/08/15
Publisher: 一般社団法人日本物理学会
ISSN： 1342-8349
Fast Ignition research with PW Laser : Numerical simulation of Non-spherical Implosion

Nagatomo H., Ohtushi N., Johzaki T., Sunahara A., Mima K.

Meeting abstracts of the Physical Society of Japan　58　(1)　244-244　2003/03/06
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Numerical analysis of initial imprint suppression with radiation-confined foam

OHNISHI Naofumi, NISHIMURA Hiroaki

Meeting abstracts of the Physical Society of Japan　58　(1)　244-244　2003/03/06
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Suppression of Rayleigh-Taylor instability by Self-emission Target

Sunahara A., Nishihara K., Fujioka S., Ohnishi N., Ikegawa T.

Meeting abstracts of the Physical Society of Japan　58　(1)　230-230　2003/03/06
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
29aZL-10 ダブル・アブレーション構造によるレイリー・テイラー不安定性の抑制

藤岡慎介, 砂原淳, 大西直文, 白神宏之, 重森啓介, 中井光男, 疇地宏, 西原功修, 山中龍彦, PE, GO, MT, Tグループ

日本物理学会講演概要集　58　(1)　2003/03/06
Publisher: 一般社団法人日本物理学会
ISSN： 1342-8349
Effects of Rotation on Neutrino Heatings in Collapse-Driven Supernovae

固武慶, 大西直文, 山田章一, 佐藤勝彦, 佐藤勝彦

日本天文学会年会講演予稿集　2003　2003

ISSN： 1347-0639
26aB06 Suppression of Ablative Rayleigh-Taylor Instability n High-Z Material Doped Laser-Fusion Target

FUJIOKA Shinsuke, SUNAHARA Atsushi, OHNISHI Naofumi, AZECHI Hiroshi, SHIRAGA Hiroyuki, NAKAI Mitsuo, SHIGEMORI Keisuke, NAGAI Keiji, NORIMATSU Takayoshi, NISHIHARA Katsunobu, IZAWA Yasukazu

(20)　149-149　2003
Publisher: プラズマ・核融合学会
28aA06P Radiation hydrodynamics of implosion with gold cone target for fast ignition

NAGATOMO Hideo, OHNISHI Naofumi, JOHZAKI Tomoyuki, SUNAHARA Atsushi, MIMA Kunioki

(20)　217-217　2003
Publisher: プラズマ・核融合学会
Three-Dimensional Simulation of an Accretion Flow with Radiative Transfer in a Close Binary System

Sato Junichi, SAWADA Keisuke, MATSUYAMA Shingo, OHNISHI Naofumi

2003　114-115　2003
Publisher: 日本流体力学会

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Three-dimensional numerical simulations of an accretion disc in a close binary system were performed by solving the Euler equations with radiative transfer. We used the one-dimensional (tangent-slab) approximation to calculate the radiative transfer for the vertical directions of the disc. The cooling effect of the disc is considered by discharging energy in only this directions. The influence of radiative cooling has been accounted for by assuming a specific heat ratio γ which is smaller than that of a mono-atomic gas (=5/3). In the present study, the specific heat ratio was assumed to be constant while radiative cooling effect was included as the non-adiabatic process. Our numerical simulations with radiative transfer demonstrated that spiral shocks existed in three-dimensional disc. It was found that its feature approached in the case of a lower γ but its tendency was weaker than that of two-dimensional simulation.
Fast Ignition Research with PW Laser-Numerical simulation of Non-spherical Implosion

Nagatomo H, Ohnishi N, Johzaki T, Mima K, Nishihara K, Yamada S, Takabe H, PW grop, Yamanaka T

Meeting abstracts of the Physical Society of Japan　57　(2)　179-179　2002/08/13
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
24pWJ-10 Numerical analysis of Non-spherical implosion using 2-D

Nagatomo H., Ohnishi N., Mima K., Sawada K., Takabe H.

Meeting abstracts of the Physical Society of Japan　57　(1)　179-179　2002/03/01
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Hydrodynamic Numerical Simulations of Accretion Discs with Radiative Cooling in a Close Binary System

SATO Junichi, SAWADA Keisuke, OHNISHI Naofumi

2002　120-121　2002
Publisher: 日本流体力学会

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Two-dimensional numerical simulations of accretion disks in a close binary system were performed by solving the Euler equations with radiative transfer. We used the flux limiting diffusion approximation to calculate the radiative transfer. The cooling effect of the disk is considered by discharging energy in the vertical directions from the top and bottom surface of the disk. The influence of radiative cooling has been accounted for by assuming a specific heat ratioγwhich is smaller than that of a mono-atomic gas (=5/3). In the present study, the specific heat ratio was assumed to be constant while radiative cooling effect was included as the non-adiabatic process. Our calculation showed that in the neighborhood of compact star a disk structure appears and the spiral shocks were formed. Spiral shocks also appear at the outer edge of the disk but are found to be unstable. It was found that the mass of the disk became larger when radiative cooling effect was accounted for than that assumingγ=5/3.
Development of Integrated Implosion Code : Numerical analysis of RT instability at short wavelength

Nagatomo H., Ohnishi N., Mima K., Sawada K., Takabe H.

Meeting abstracts of the Physical Society of Japan　56　(2)　144-144　2001/09/03
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Growhh of the intemal initial perturbations and control of the hydrodynamic turbulence in the structured target

Nishikino M, Shiraga H, Fujita K, Ohnishi N, Fujioka S, Ochi Y, Miyanaga N, Nagai K, Nishimura H, Sakaiya T, Shigemori K, Nakai M, Azechi H, Yamanaka T, Mt Go, T Groups

Meeting abstracts of the Physical Society of Japan　56　(2)　155-155　2001/09/03
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Dissociation model of deuterium and hydrogen for Integrated Implosion Code

Nagatomo H., Sakamoto Y., Mima K., Ohnishi N., Takabe H., Sawada K., Nishihara K.

Meeting abstracts of the Physical Society of Japan　56　(1)　184-184　2001/03/09
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Analysis of R-T Instability using New Integrated Implowion Code : Radiation Effect

Nagatomo H., Ohnishi N., Takabe H., Mima K., Sawada K., Nishihara K.

Meeting abstracts of the Physical Society of Japan　55　(2)　145-145　2000/09/10
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Numerical Analysis of Hydrodynamic Instability Growth due to Laser Non-uniformity

Ohnishi N., Nagatomo H., Takabe H., Nishimura H.

Meeting abstracts of the Physical Society of Japan　55　(2)　146-146　2000/09/10
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Analysis of Rayleigh-Taylor Instability using New Integrated Implosion Code

Nagatomo H., Ohnishi N., Sawada K., Takabe H., Mima K.

Meeting abstracts of the Physical Society of Japan　55　(1)　130-130　2000/03/10
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Numerical Analysis of Initial Imprint using Multi-Dimensional Radiation Hydrodynamic Code II

Ohnishi N., Nagatomo H., Takabe H., Nishimura H.

Meeting abstracts of the Physical Society of Japan　55　(1)　138-138　2000/03/10
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
29pB22P Development of New Integrated Implosion Code and Implosion Analysis

(17)　195-195　2000
Publisher: プラズマ・核融合学会
26pYF-10 Imprint mitigation by using multi-density form-hybrid targets

Nishimura H, Nakai M, Ohnishi N, Nishikino M, Matsuoka M, Izumi N, Shiraga H, Miyanaga N, Nagai K, Norimatsu T, Takabe H, Azechi H, Yamanaka T, GO.T.Mt Sections

Meeting abstracts of the Physical Society of Japan　54　(2)　173-173　1999/09/03
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
25pYF-4 Numerical Analysis of Initial Imprint using MultiDimensional Radiation Hydrodynamin Code

Ohnishi N, Nagatomo H, Takabe H, Nishimura H, Nishikino M, Shiraga H

Meeting abstracts of the Physical Society of Japan　54　(2)　155-155　1999/09/03
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
25pYF-3 Analysis of Hydrodynamic Instablity using Implicit Integrated Implosion Code

Nagatomo H, Ohnishi N, Takabe H, Mima K

Meeting abstracts of the Physical Society of Japan　54　(2)　155-155　1999/09/03
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
26pYF-9 Dependence of imprint mitigation on x-ray pre irradiation intensity

Nishikino M, Shiraga H, Azechi H, Nakai M, Miyanaga N, Matsuoka M, Shigemori K, Nagaya T, Honda H, Nishimura H, Oonishi N, Takabe H, Mima K, Yamanaka T, Mt.Go.T Groups

Meeting abstracts of the Physical Society of Japan　54　(2)　172-172　1999/09/03
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
31p-XH-5 Development of High Accuracy Integrated Implosion Code ILESTA-2D

Nagatomo H., Ohnishi N., Takabe H., Mima K.

Meeting abstracts of the Physical Society of Japan　54　(1)　837-837　1999/03/15
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
31p-XH-8 Numerical Study of Implosion Stabilization with X-ray Radiation Transport using Integrated Implosion Code II

Ohnishi N., Nagatomo H., Takabe H., Nishimura H., Nishikino M., Shiraga H., Mima K.

Meeting abstracts of the Physical Society of Japan　54　(1)　837-837　1999/03/15
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
30p-XH-10 Suppression of initial imprinting of laser irradiation nonuniformity with x-ray pre-irradiation and control of pre-expansion plasma

Nishikino M, Shiraga H, Miyanaga N, Nishimura H, Izumi N, Heya M, Fujita K, Ochi Y, Niki I, Fujioka S, Azechi H, Nakai M, Shigemori K, Norimatsu T, Takagi M, Nagai K, Honda H, Oonishi N, Takabe H, Yamanaka T, Mima K, Mt Go, T Groups

Meeting abstracts of the Physical Society of Japan　54　(1)　818-818　1999/03/15
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Numerical Analysis of Hydrodynamic Instability using Integrated Implosion Code with Implicit ALE method

(16)　58-58　1999
Publisher: プラズマ・核融合学会
25pYF-5 The high gain design of foam-buffered target

Takeda T, Mima K, Azechi H, Nishimura H, Nagatomo H, Nishiguchi A, Sunahara A, Ohnishi N, Honda M

Meeting Abstracts of the Physical Society of Japan　54　(0)　156-156　1999
Publisher: 一般社団法人日本物理学会
ISSN： 1342-8349
1)レーザー核融合研究におけるビジュアライゼーション(〔情報センシング研究会情報ディスプレイ研究会〕合同)(画像変換技術)

福田優子, 岡本匡代, 西原功修, 長友英夫, 砂原淳, 大西直文

映像情報メディア学会誌 : 映像情報メディア　52　(11)　1598-1598　1998/11/20
Publisher: 一般社団法人映像情報メディア学会
ISSN： 1342-6907
Implsoion of indirect-direct foam hybrid targets

NISHIMURA H., SHIRAGA H., FUJITA K., AZECHI H., HEYA M., NISHIKINO M., OCHI Y., NIKI I., FUNAKURA J., NORIMATSU T., NAGAI K., OHNISHI N., TAKABE H., MIMA K., GO-SECTIONS, T-SECTIONS, MT-SECTIONS

Meeting abstracts of the Physical Society of Japan　53　(2)　962-962　1998/09/05
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Numerical Study of Implosion Stabilization with X-ray Radiation Transport using Integrated Implosion Code

OHNISHI N., NAGATOMO H., NISHIMURA H., TAKABE H., MIMA K.

Meeting abstracts of the Physical Society of Japan　53　(2)　980-980　1998/09/05
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Visualiztion on Inertial Confinement Fusion (ICF) Analysis of Sumuration Data on Super Computer

FUKUDA Yuko, OKAMOTO Masayo, NISHIHARA Katsunobu, NAGATOMO Hideo, SUNAHARA Atsushi, OHNISHI Naofumi, HONDA Tetsuya, YODA Yoshiaki

IEICE technical report. Electronic information displays　98　(151)　1-6　1998/06/25
Publisher: The Institute of Electronics, Information and Communication Engineers

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In Research of Inerttial Confinement Fusion (ICF), computer simulation has been given an important role. Since the output data from the computer simulation is increased according to the recent rapid progress in speed and main memory of super computers. Here we report some examples and difficulties of scientific visualization in our research.
Paralell Computing in Plasma and Fusion Research : High Energy Density Plasmas

TAKABE H., NAGATOMO H., SUNAHARA A., OHNISHI N., NARUO S., YODA Y., SENTOKU Y., RUHI H., FUKUDA Y., MIMA K.

Meeting abstracts of the Physical Society of Japan　53　(1)　831-831　1998/03/10
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Numerical Simulation on Linear and Non-linear Development of Rayleigh-Taylor Instability by ILESTA-2D

NAGATOMO H., OHNISHI N., NARUO S., TAKABE H., MIMA K.

Meeting abstracts of the Physical Society of Japan　53　(1)　814-814　1998/03/10
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Development of Radiation Transport Scheme in 2D Integrated Implosion Code

OHNISHI N., NAGATOMO H., SUNAHARA A., NISHIMURA H., TAKABE H., MIMA K.

Meeting abstracts of the Physical Society of Japan　53　(1)　823-823　1998/03/10
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
6p-YM-10 Development of the Compressive Complex Hydrodynamic Integrated Code IV : Nonlinear evolution Scenario of Rayleigh-Tayor Instability

Nagatomo H., Ohnishi N., Takabe H., Mima K.

Meeting abstracts of the Physical Society of Japan　52　(2)　929-929　1997/09/16
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
6p-YM-8 Development of Compressive Complex Hydrodynamic Integrated Code II : Numerical Analysis of R-T Instability Experiments using Multi-dimensional Nonlinear Thermal Conduction Scheme

Ohnishi N., Nagatomo H., Takabe H., Mima K.

Meeting abstracts of the Physical Society of Japan　52　(2)　928-928　1997/09/16
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
6p-YN-7 Development of Compressible, Complex, Hydrodynamic Integrated Code I : Overview and Plan

Takabe H., Nagatomo H., Sunahara A., Ohnishi N., Naruo S., Nishimura H., Azechi H., Mima K.

Meeting abstracts of the Physical Society of Japan　52　(2)　928-928　1997/09/16
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
29p-YG-7 Development of Integrated Implosion Code(3) : Rezoning and Remapping Algorithm in Arbitrary Lagrangian Eulerian Method

Nagatomo H, Takabe H, Ohnishi N, Mima K

Meeting abstracts of the Physical Society of Japan　52　(1)　853-853　1997/03/17
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
29p-YG-6 Development of Integrated Implosion Code(2) : Numerical Method for Solving Diffusion Equation in Non-orthogonal Meshes

Ohnishi N, Takeuchi H, Nagatomo H, Takabe H, Mima K

Meeting abstracts of the Physical Society of Japan　52　(1)　853-853　1997/03/17
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
29p-YG-5 Development of Integrated Implosion Code(1) : Overview and Plan

Takabe H, Nagatomo H, Kato S, Ohnishi N, Naruo S, Sunahara A, Honda M, Azechi H, Mima K

Meeting Abstracts of the Physical Society of Japan　52　(0)　853-853　1997
Publisher: 一般社団法人日本物理学会
ISSN： 1342-8349
A effect of equation of state(EOS)for growing an initial shock wave

Takeuchi H., Ohnishi N., Sunahara S., Nagatomo H., Takabe H.

Abstracts of the meeting of the Physical Society of Japan. Sectional meeting　1996　(4)　193-193　1996/09/13
Publisher: The Physical Society of Japan (JPS)

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Books and Other Publications 1

プラズマ原子分子過程ハンドブック

浜口智志, 村上泉, 加藤太治, 砂原淳

大阪大学出版会　2011/03/31

Presentations 66

Numerical Analysis of Hydrodynamic Instability in Magnetized Laser Ablation Flow International-presentation

Ayako Ishii, Yasuhiro Kuramitsu, Taichi Morita, Youichi Sakawa, Hideaki Takabe

10th International Conference on High Energy Density Laboratory Astrophysics　2014/05/12
Impulse Control for Stable Flight of Beamed Energy Vehicle International-presentation

Masayuki Takahashi, Yoshiaki Kageyama

International High Power Laser Ablation and Beamed Energy Propulsion　2014/04/21
回転電場による無電極プラズマ推進機の数値解析

野村亮介, 中村隆宏, 西田浩之

日本航空宇宙学会北部支部2014年講演会ならびに第15回再使用型宇宙推進系シンポジウム　2014/03/10
Hydrodynamic Instabilities Relevant to High Speed Plasma Flows International-presentation

International Workshop on Flow Dynamics related to Energy, Aerospace and Material Processing　2013/09/10
誘電体バリア放電と誘起流れのハイブリッドシミュレーション

杉本和弥, 高橋聖幸

日本機械学会2013年度年次大会　2013/09/08
輻射流体シミュレーションによるX線発光の予測

2012年度レーザー励起X線源とその応用研究会　2012/12/06
Prediction of EUV Emission from Laser Ablation Plasma with Anisotropic Radiative Transfer Solver International-presentation

Atsushi Sunahara, Hiroaki Nishimura

15th International Workshop on Radiative Properties of Hot Dense Matter　2012/11/05
Toward an Accurate Numerical Simulation of Radiation Hydrodynamics in Laser Ablation Plasmas International-presentation

9th International Conference on High Energy Density Laboratory Astrophysics　2012/04/30
低密度プラズマのための非等方輻射を伴う流体計算手法

砂原淳

第25回数値流体力学シンポジウム　2011/12/19
大気圧プラズマによる流れ場生成過程の粒子シミュレーション

奥野靖之, 杉本和弥, 江波戸翔一

第10回応用物理学会プラズマエレクトロニクス分科会新領域研究会／電気学会プラズマ技術委員会プラズマ研究会　2011/12/15
プラズマ誘起液中化学プロセスにおける液中化学反応シミュレーション

北野勝久, 井川聡, 谷篤史

Plasma Conference 2011　2011/11/22
Development of Laser Ablation Plasma by Anistropic Self-Radiation International-presentation

Atsushi Sunahara

7th International Conference on Inertial Fusion Sciences and Applications　2011/09/12
Trigger physics of gravitationally collapsing supernova explosion in three-dimension and its model experiments International-presentation

3rd Japan-France Workshop and School on High Energy Density Science　2011/01/09
Computational study of stationary shock wave instability toward a labora- tory experiment International-presentation

52nd Annual Meeting of the APS Division of Plasma Physics　2010/11/08
Computational study of shock instability and its application International-presentation

Naofumi Ohnishi, Wakana Iwakami Nakano, Kei Kotake, Shoichi Yamada, Yuichiro Suzuki, Yousuke Ogino

China-Japan CPU Seminar on Laser Plasma Physics　2010/10/13
Three-dimensional simulation of stationary shock wave instability International-presentation

Naofumi Ohnishi, Wakana Iwakami Nakano, Kei Kotake, Yuichiro Suzuki, Shoichi Yamada, Hideaki Takabe

ISWI 2010: The Shock and High Strain Rate Properties of Matter　2010/09/07
プラズマ液体プロセスにおける液中イオン・ラジカル拡散の数値解析

大西直文, 北野勝久, 谷篤史, 井川聡

第57回応用物理学関連連合講演会　2010/03/17
A new attempt for radiation hydrodynamics simulation with anisotropic and non-equilibrium distribution International-presentation

N. Ohnishi, Y. Ogino

6th International Conference on Inertial Fusion Sciences and Applications　2009/09/06
Computational study of shock wave control by pulse energy deposition International-presentation

M. Tate, Y. Ogino

27th International Symposium on Shock Waves　2009/07/19
非等方性を考慮した輻射輸送解法と流れ場との結合計算

菅井健一

第22回数値流体力学シンポジウム　2008/12/17
非等方性を考慮した輻射輸送計算による極端紫外光源プラズマの解析

砂原淳

第25回プラズマ・核融合学会年会　2008/12/02
Effects of neutrino heating and g-modes on SASI with steady-state initial conditions International-presentation

Asymmetric Instabilities in Stellar Core Collapse　2008/06/30
Destruction of nanograins by grain-grain collisions International-presentation

Eduardo Bringa, Bruce Remington, George Gilmer, Roger Minich, Yasutaka Yamaguchi, Alexander Tielens

International Conference on HEDP/HEDLA-08　2008/04/12
Roles of shock instability interacting with neutrino radiation on supernova explosions International-presentation

Wakana Iwakami, Kenichi Sugai, Kei Kotake, Shoichi Yamada

International Conference on HEDP/HEDLA-08　2008/04/12
輻射場の非等方性を考慮したアブレーションプラズマの数値解析

菅井健一, 砂原淳

日本物理学会第63回年次大会　2008/03/22
気体駆動型レーザー推進における推力発生の数値シミュレーション

荻野要介

平成19年度衝撃波シンポジウム　2008/03/17
Computational study of thrust generation from laser-driven blast wave International-presentation

Naofumi Ohnishi, Yousuke Ogino

5th International Symposium on Beamed Energy Propulsion　2007/11/12
Standing accretion shock instability: numerical simulations of core-collapse supernova and its laboratory experiment International-presentation

Wakana Iwakami, Kei Kotake, Shoichi Yamada, Shinsuke Fujioka, Hideaki Takabe

5th International Conference on Inertial Fusion Sciences and Applications　2007/09/09
Numerical analysis of nanograin collision by classical molecular dynamics International-presentation

E. M. Bringa, B. A. Remington, G. Gilmer, R. Minich, Y. Yamaguchi, A. G. G. M. Tielens

5th International Conference on Inertial Fusion Sciences and Applications　2007/09/09
Code development and numerical analysis of radiation hydrodynamics relevant to laboratory and astrophysical plasmas International-presentation

2006 International Workshop on Laboratory Astrophysics　2006/07/24
Toward the Optimal Operation of laser-driven in-tube accelerator International-presentation

N. Ohnishi, Y. Ogino, K. Sawada, T. Ohtani, K. Mori, A. Sasoh

44th AIAA Aerospace Science Meeting and Exhibit　2006/01/09
過渡的衝突励起X線レーザーにおけるプラズマ媒質の数値解析II

大西直文, 錦野将元, 佐々木明

第19回数値流体力学シンポジウム　2005/12/13
Numerical simulation of laser-driven in-tube accelerator operation International-presentation

N. Ohnishi, Y. Ogino, K. Sawada, T. Ohtani, K. Mori, A. Sasoh

4th International Symposium on Beamed Energy Propulsion　2005/11/15
過渡衝突励起X線レーザーのゲインにおけるプラズマ媒質の二次元効果

大西直文, 錦野将元, 佐々木明

日本物理学会 2005年秋季大会　2005/09/19
Numerical analysis of plasma medium of collisional transient excited x-ray lasers International-presentation

N. Ohnishi, M. Nishikino, A. Sasaki

4th International Conference on Inertial Fusion Sciences and Applications　2005/09/04
過渡衝突励起X線レーザーにおけるプラズマ媒質の密度分布の影響

大西直文, 錦野将元, 佐々木明

日本物理学会第60回年次大会　2005/03/24
レーザー駆動管内加速装置の数値シミュレーション

大西直文, 荻野要介, 澤田恵介, 大谷俊朗, 佐宗章弘

平成16年度衝撃波シンポジウム　2005/03/18
Numerical analysis of laser-driven in-tube accelerator operation International-presentation

N. Ohnishi, Y. Ogino, K. Sawada, T. Ohtani, A. Sasoh

43rd AIAA Aerospace Science Meeting and Exhibit　2005/01/10
過渡的衝突励起X線レーザーにおけるプラズマ媒質の数値解析

大西直文, 錦野将元

第18回数値流体力学シンポジウム　2004/12/15
自己放射により駆動される慣性核融合ターゲットの数値シミュレーション

大西直文, 砂原淳, 藤岡慎介, 西原功修

第17回数値流体力学シンポジウム　2003/12/17
Computational study on direct-drive implosion of radiatively ablated target International-presentation

N. Ohnishi, A. Sunahara, S. Fujioka, K. Nishihara

3rd International Conference on Inertial Fusion Sciences and Applications　2003/09/07
輻射閉じ込めフォームによる初期刻印抑制の数値解析

大西直文, 西村博明

日本物理学会第58回年次大会　2003/03/28
慣性核融合における輻射閉じ込め型ターゲットの数値シミュレーション

大西直文, 西村博明

第16回数値流体力学シンポジウム　2002/12/16
Computational study of a radiation confined foam layer to suppress hydrodynamic perturbation growth International-presentation

N. Ohnishi, H. Nishimura

44th Annual Meeting of the APS Division of Plasma Physics　2002/11/11
Radiation hydrodynamic simulation of laser irradiated low-density media International-presentation

N. Ohnishi, H. Nagatomo, H. Takabe

2nd International Conference on Inertial Fusion Sciences and Applications　2001/09/09
Radiation effects on hydrodynamic perturbation growth due to non-uniform laser irradiation International-presentation

9th international workshop on radiative properties of hot dense matter　2000/10/30

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(プロシーディング) Journal of Quantitative Spectroscopy and Radiation Transfer vol. 71 Elsevier 2001 551 560
Reduction of the initial imprint by radiation in foam buffered targets International-presentation

42nd annual meeting of the APS division of plasma physics　2000/10/23

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(プロシーディング) Bulletin of the American Physical Society Series II, vol. 45, No. 7 APS 2000 223
レーザー強度非一様による流体不安定性発展の解析

日本物理学会第55回年会　2000/09/22

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(プロシーディング) 日本物理学会講演概要集第55巻第2号日本物理学会 2000
Numerical analysis of imprint mitigation scheme using multi-dimensional radiation hydrodynamic code International-presentation

4th International Conference on Supercomputing in Nuclear Applications　2000/09/04

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(プロシーディング) Proceedings of the 4th International Conference on Supercomputing in Nuclear Applications SNA2000 Office 2000 RPS096
多次元輻射流体コードを用いたICFターゲットの安定化に関する研究

第3回核融合エネルギー連合講演会　2000/06/12

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(プロシーディング) 第3回核融合エネルギー講演会予稿集プラズマ・核融合学会 2000 155
多次元輻射流体コードを用いた初期インプリントの数値解析II

日本物理学会 2000年春の分科会　2000/03/22

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(プロシーディング) 日本物理学会講演概要集第55巻第1号日本物理学会 2000
多次元輻射流体コードによる慣性核融合ターゲットの初期インプリント解析

第13回数値流体力学シンポジウム　1999/12/21

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(プロシーディング) 第13回数値流体力学シンポジウム講演論文集日本数値流体力学会 1999 E01-3
Computatinal study of x-ray radiation effects on hydrodynamic instability International-presentation

International Forum on Advanst High Power Lasers and Applications　1999/11/01

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(プロシーディング) Proceedings of SPIE vol. 3886 SPIE 2000 473 480
多次元輻射流体コードを用いた初期インプリントの数値解析

日本物理学会 1999年秋の分科会　1999/09/24

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(プロシーディング) 日本物理学会講演概要集第54巻第2号第2分冊日本物理学会 1999 155
Numerical analysis of imprint mitigation with soft x-ray radiation using integrated code International-presentation

First International Conference on Inertial Fusion Sciences and Applications　1999/09/12

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(プロシーディング) Inertial Fusion Sciences and Applications 99 Elsevier 2000 184 187
Computational study of laser imprint mitigation with x-ray radaition using integrated code in ICF targets International-presentation

International Seminar on Atomic Processes in Plasmas　1999/07/29

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(プロシーディング) Proceedings of the International Seminar on Atomic Processes in Plasmas NIFS 2000 188 189
統合コードを用いたX線輻射輸送による爆縮安定化の研究II

日本物理学会第54回年会　1999/03/28

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(プロシーディング) 日本物理学会講演概要集第54巻第1号日本物理学会 1999
統合コードを用いた輻射輸送による爆縮安定化の研究

プラズマ・核融合学会第15回年会　1998/12/01

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(プロシーディング) （社）プラズマ・核融合学会第15回年会予稿集プラズマ・核融合学会 1998 258
統合爆縮コードを用いたX線輻射輸送による爆縮安定化の研究

日本物理学会 1998年秋の分科会　1998/09/25

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(プロシーディング) 日本物理学会講演概要集第53巻第2号第4分冊日本物理学会 1998 980
統合爆縮コードにおける輻射輸送計算スキームの開発 International-presentation

輻射輸送・輻射流体力学研究会　1998/06/10

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(プロシーディング) 筑波大学計算物理学研究センター研究報告 UTCCP Report 98-3 筑波大学計算物理学研究センター 1998 29 40
二次元輻射流体コードを用いたX線輻射による爆縮安定化の研究

第2回核融合エネルギー連合講演会　1998/06/01

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(プロシーディング) 第2回核融合エネルギー講演会予稿集プラズマ・核融合学会 1998 125
二次元統合爆縮コードにおける輻射輸送スキームの開発

日本物理学会第53回年会　1998/03/30

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(プロシーディング) 日本物理学会講演概要集第53巻第1号第4分冊日本物理学会 1998 823
二次元圧縮性ALE法に基づく統合爆縮コードの開発

第11回数値流体力学シンポジウム　1997/12/18

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(プロシーディング) 第11回数値流体力学シンポジウム講演論文集日本数値流体力学会 1997 103 104
圧縮性複雑流体統合コードの開発 -II- ＝多次元非線形熱伝導スキームを用いたR-T不安定実験の解析＝

日本物理学会 1997年秋の分科会　1997/10/05

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(プロシーディング) 日本物理学会講演概要集第52巻第2号第4分冊日本物理学会 1997 928
統合爆縮コードの開発(2) ＝非直交格子中の多次元拡散方程式の解法＝

日本物理学会第52回年会　1997/03/28

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(プロシーディング) 日本物理学会講演概要集第52巻第1号第4分冊日本物理学会 1997 853
高密度爆縮用二次元ラグランジアンコードの開発

第10回数値流体力学シンポジウム　1996/12/19

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(プロシーディング) 第10回数値流体力学シンポジウム講演論文集日本数値流体力学会 1996 42 43

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Research Projects 15

電荷制御に基づく革新的イオン風生成技術によるエアロイオニクスの確立

大西直文, 佐藤慎太郎

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(B)

Institution: 東北大学

2024/04/01 - 2027/03/31
Macroscopic structures governed by electron dynamics in non-equilibrium plasmas

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: Osaka University

2022/04/01 - 2027/03/31
表面電荷制御による革新的流体制御技術の確立

大西直文, 佐藤慎太郎, 蟹江澄志, 野々村拓, 松野隆, 小室淳史

Offer Organization: 日本学術振興会

System: 科学研究費助成事業基盤研究(A)

Category: 基盤研究(A)

Institution: 東北大学

2020/04/01 - 2023/03/31

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以前より取り組んでいた小型化・多電極化によるプラズマアクチュエータ（PA）の低電圧化に引き続き取り組み，多電極化した PA の段を追うごとに加速されていることが PIV（Particle Image Velocimetry）で確認でき，期待通りの性能が 1.5 kV 程度の直流電圧と高速スイッチだけで得られた．次に，印刷電極によって小型化・多電極化した PA の性能評価を行った．銀ナノインクを用いて電極をインクジェット印刷した後，銅メッキすることで，従来の銅テープを用いた電極と同程度の抵抗値に抑えつつ，電極厚さが小さく加工精度の高い電極を誘電体上に製作することができた．性能評価は PIV による流速の測定，および放電による電磁ノイズの影響を受けにくい振り子式推力計による推力計測を行った．いずれの結果も従来の銅テープ電極を用いた性能に劣るどころか，むしろ性能が向上する結果を得た．走査電子顕微鏡で電極端を観察したところ，印刷電極には印刷時の濡れ性に起因した湾曲構造があり，これと電極厚さが小さくなったことが放電特性を向上させ，結果として気流生成能力も向上させた可能性を示唆している．また，表面電荷を計測するために，ポッケルス素子を用いた表面電位センサの開発を行った．その結果，一般的な表面バリア放電における電位の時空間変化を計測することに成功し，印加する電圧の正負の極性の違いにより誘電体表面の帯電分布に変化が生じることが分かった．さらに，鋸歯電極にした場合のプラズマアクチュエータの誘起速度をシングルピクセル PIV 技術を利用して計測した．鋸歯電極にした場合，誘起速度が安定して高くなることを確認した．またプラズマアクチュエータのバースト駆動による誘起流れを PIV で測定し，パラメータによって流れ場の分類ができることを明らかにした．
Development of Advanced Electrodeless Electromagnetic Acceleration Method and Analysis of Physics Phenomena Using Helicon High-Density Plasma

Shunjiro Shinohara

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: Tokyo University of Agriculture and Technology

2017/04/01 - 2020/03/31

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Specific impulse in the electric prupulsion is higher than the cheical one, and it is crucial to develop electric propulsion rockets usin plasmas for future electric satellite, interplanetary transport etc. The development of the plasma rockets with long lige with high power is challenging for, e.g., a deep space exploration to exceed "Hayabusa" project. In this research, we have succeeded to obtain the following results, using a proposed concept of "electrodeless" condition, which has entire processes of hihg-density plasma production and novel electromagnetic acceleration. Here, we have investigated physical phenomena with advanced, developed diagnostics and therory/simulation, leading to new findings and established a proto-type model by optimization: plasma pridcution with the smallest and the largest diameters (0.05-74 cm), new gas feeding system (internal and supersonic types), rotating magnetic field and m = 0 half cycle accerelation methods.
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

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.
Discharge induced in a high-energy electromagnetic beam and its engineering applications

KOMURASAKI KIMIYA

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (S)

Category: Grant-in-Aid for Scientific Research (S)

Institution: The University of Tokyo

2015/05/29 - 2020/03/31

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We conducted experiments and numerical analyzes on the discharge phenomena induced by high-energy laser and millimeter-wave beams. Regarding the laser discharge, experiments clearly show that there is a unique correlation between the spatially local laser intensity and the local discharge evolution speed. The comparison with the one-dimensional analysis strongly suggested the influence of the two-dimensionality of the laser intensity distribution. For millimeter-wave discharges, it was concluded that the rapid evolution of the discharge wavefront and the spatially non-uniformly generated plasma structure form a pair and conserve thermodynamic quantities. For both types of discharges, measurement techniques and physical models have been studied and improved to the level where the spatial distribution of electron temperature, plasma density, etc. can be compared in detail. Further, a high-power gyrotron designed for atmospheric millimeter-wave discharge was constructed.
Experimental demonstration of unsteady detatched shock wave and theory development toward its active control

Ohnishi Naofumi

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: Tohoku University

2014/04/01 - 2017/03/31

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An instability of a detached shock wave formed in front of a blunt body was investigated by numerical simulations and experiments using a ballistic range toward an engineering application of unsteady shock waves. The experiments successfully demonstrated that the detached shock wave is unstable under low-specific-heat-ratio and high-Mach-number conditions, and the numerical simulations were able to predict the critical condition of the instability. Moreover, the front shape of the projectile equipped with an edge is preferable to destabilize the detached shock wave, and acoustic waves emitted from the edge play a significant role on inducing the instability.
Development of high spatial and temporal resolusion interference imaging system by using coherent soft x-ray

Tomita Takuro, HASEGAWA Noboru, NISHIKINO Masaharu, KAWACHI Tetsuya, SUEMOTO Tohru, OHNISHI Naofumi, EYAMA Takashi, KAKIMOTO Naoya, IZUTSU Rui

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: The University of Tokushima

2013/04/01 - 2016/03/31

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In order to discuss the nanometer-scaled precise ablation phenomena induced by femtosecond laser irradiation, we constructed the femtosecond laser pump and the soft x-ray probe time resolved imaging system. From the reflective imaging, we succeed to reveal the expansion process of the exfoliated film associated with the femtosecond laser ablation. In addition, it has found that the vertical shape of the exfoliated films is similar to the intensity profile of the incident laser beam used for the laser ablation. Moreover, by using the soft x-ray interferometry, the formation process of the exfoliated film that has formed within less than one nanosecond, and the formation process of the ablation crater has successfully observed.
A study of the initial process of the femtosecond laser ablation by using the soft x-ray laser probe.

HASEGAWA NOBORU, NISHIKINO MASAHARU, ISHINO MASAHIKO, NANBA SHINICHI, OHNISHI NAOFUMI

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 Atomic Energy Agency

2013/04/01 - 2016/03/31

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We have succeeded in observation of the details of the temporal evolution of the ablating surfaces induced the femto-second laser by using the shingle-shot soft x-ray laser probe system. The ablation front with a solid or the melted surface and the expansion front with thin film structure were observed. Especially the sample of Au, the expansion front separated from the ablation front was thin, dense and smooth, therefore it works as the beam splitter for the soft x-rays at the time within 1 ns after the laser irradiation. The surface roughness of expansion front was better than a few nm, and the formation of nano-bubble structures were expected below the ablation front. In addition we have observed the result of the theoretical simulation for the femtosecond ablation process within 100 ps by using the molecular dynamics (MD) simulation.
Research and Development of a Novel Electrodeless Plasma Rocket Engine Using a Helicon Source

SHINOHARA Shunjiro, TANIKAWA Takao, HADA Tohru, FUNAKI Ikkoh, NISHIDA Hiroyuki, YAMAGATA Yukihiko, INOMOTO Michiaki, TAKAHASHI Kazunori, ONISHI Naofumi, KUWAHARA Daisuke

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (S)

Category: Grant-in-Aid for Scientific Research (S)

2009/05/11 - 2014/03/31

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Fuel cost using electric propulsion is better (specific impulse is higher) than chemical one. The contact erosion between a plasma and electrodes, producing and accelerating the plasma, leads to a lifetime shortage. To overcome this, our study had "electrodeless" conditions. Helicon sources have been developed and characterized: The largest (smallest) diameter of 74 (0.3) cm was achieved, and the scalings of the production efficiency have been established. Roles of a helicon and a TG waves were examined. We have proposed many acceleration schemes: A helicon source alone showed the maximum specific impulse of 3,000 s and the maximum ratio of thrust to power of 16 mN/kW. The excited magnetic field penetration and the ion velocity increase were found in the RMF scheme. Methods such as REF and PA/ICR were also advanced. We have developed the two-dimensional measurement systems using laser induced fluorescence and high-resolution spectroscopy, and the various types of the thrust stands.
Quest for the unified picture of the explosion mechanism of supernovae and the central engine of gamma-ray bursts

SATO Katsuhiko, HASHIMOTO Masaaki, SUZUKI Hideyuki, YAMADA Shoichi, NAGATAKI Shigehiro, KOTAKE Kei, TAKIWAKI Tomoya, WATANABE Gentaro, OHNISHI Naohumi, SUMIYOSHI Kohsuke, FUJIMOTO Shinichiro, KIUCHI Kenta, IWAKAMI Wakana, SAWAI Hidetomo, YASUTAKE Nobutoshi, NISHIMURA Nobuya, SUWA Yudai, NAKAZATO Kenichiro, NAGAKURA Hiroki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (S)

Category: Grant-in-Aid for Scientific Research (S)

2007 - 2011

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Advanced studies on the explosion mechanism of core-collapse supernovae and central engine of gamma-ray bursts were performed in this program, giving fruitful and state-of-the-art results. Lots of large-scale numerical simulations were done for the purpose, and in some cases cutting-edge simulations were performed using the K-computer. We also succeeded to obtain fruitful and noteworthy results on lots of phenomena accompanying core-collapse supernovae and gamma-ray bursts, such as gravitational waves, neutrino emissions, explosive nucleosynthesis including r-process nucleosynthesis, and ultra-high energy cosmic rays. For the above reasons, it is concluded that we could achieve great success to obtain cutting edge results in this program, which is more than we expected. Simultaneously, our five-year mission has ended successfully, leaving future works and direction of this field.
Mechanism of Stationary Shock Wave Instability and Its Application

OHNISHI Noafumi

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

2009 - 2010

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Three-dimensional numerical simulations were conducted using the discontinuous Galerkin (DG) finite-element method to clarify mechanism of bow-shock instability, which has been experimentally observed for a blunt body. The most favorable flux functions and numerical conditions were explored through the comparisons among them. Laser energy deposition that leads to a low-density region ahead of a bow shock was investigated for reducing the wave drag, and the effect of laser input condition was clarified with our developed code.
レーザー推進における部分電離プラズマの非平衡輻射流体計算

大西直文

Offer Organization: 日本学術振興会

System: 科学研究費助成事業若手研究(B)

Category: 若手研究(B)

Institution: 東北大学

2005 - 2006

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本年度の研究では,準定常状態を仮定した輻射の放射・吸収,およびその原子状態から電離度等の気体の状態量を計算するコードを開発し,レーザーの屈折・吸収計算とともに流体計算と結合することでレーザー駆動管内加速装置(LITA)におけるプラズマの生成,およびそれによるブラスト波の形成過程を再現することに成功した。まず,現在のLITAの実験は不活性な単原子気体を用いているので,既存のコードでエネルギー準位やレート係数を計算し,それをもとに準定常状態を仮定した各エネルギー状態の存在確率を計算した.輻射計算で得られる放射率を流体との結合計算に利用するために,広範囲の密度・温度に対応するようにテーブル化した.また,本年度の結合計算に組み込むことはできなかったが,三次元の輻射輸送計算を効率的に解くための手法についても調査を行い,宇宙機が大気圏突入時に経験する輻射流れ場に対して適用した. 開発した輻射流体コードを用いてLITAの基礎実験に対応した数値シミュレーションを行い,実験データとの比較を行った.その結果,実験で得られている衝撃波の伝搬速度や,プラズマの生成過程の様子をよく再現することができた.さらに,発光スペクトルの比較を行ったが,こちらに関してはまだ完全に一致しておらず,非平衡なプラズマの状態を記述するための計算手法に課題を残した.これに関しては現在,プラズマの非定常な状態を時間依存のレート方程式を解くことで再現することを試みている. さらに,効率的なレーザー推進システムの運用を目指して,レーザーエネルギーからいかに効率良く推進力を得るかについても調査を行った.その結果,得られる推進力は飛翔体の形状や,充填圧力に依存し,最適な条件があることがわかった.また,その傾向は実験で示唆されているものとも一致し,実験では不明瞭であった最適条件の存在を支持する結果が得られた.
非定常高温気体における輻射流体連成計算システムの構築

大西直文

Offer Organization: 日本学術振興会

System: 科学研究費助成事業若手研究(B)

Category: 若手研究(B)

Institution: 東北大学

2002 - 2003

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輻射によるエネルギー輸送を伴う流体現象は,高強度レーザーで生成されるプラズマや,宇宙機の大気突入時における極超音速流れ場のような高温気体において重要な研究課題である.このような輻射流体現象の解析には,流体現象や輻射現象を同時に扱わねばならず,これらを結合した数値計算による研究が必要である. 本研究では,輻射流体計算をなす要素計算を効率化することで,精度を保ちながら計算負荷を削減する計算システムを構築することを目的とした.昨年度の研究において,輻射の放出・吸収スペクトルを波長空間で離散化する際の波長点配置方法について調査を行ったが,本年度ではそれをさらに進めて,より少ない波長点数で精度を下げずに輻射流体計算を行う手法について検討を行った.具体的には,線スペクトルに対してそれぞれ決まった波長点数を配置し,スペクトルの裾野を捉えるための最低値をどこまでにするかをパラメータとすることで,輻射流体計算に適したパラメータを探した.地球大気に超軌道速度で突入する宇宙機周りの流れ場を想定した場合,通常詳細な計算には約百万点の波長点数が必要であると言われているが,本研究で提案した手法を用いると数千点の波長点数で輻射流体計算ができることがわかった. また,三次元輻射輸送計算の効率化についても検討し,光線追跡法で輸送計算を行う際の新しい光線配置方法を提案した.具体的には,従来用いられてきた等角度配置の代わりに,ガウスの求積法に基づく離散座標で配置する方法を提案した.これにより,高い精度で立体角積分を行うことができ,光線数カミ大幅に削減できることを確認した. さらに,具体的な輻射流体力学的事象についても研究を行い,高Z物質をドープしたプラスチックを高強度レーザー照射により加速すると,二段のアブレーション面が形成され,X線輻射によって形成されるアブレーション面で流体力学的不安定性が低減できることを確認した.
統合爆縮コードの開発とそれを用いた高温・高密度流体不安定の研究

大西直文

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: 大阪大学

1998 - 2000

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Other 11

分子動力学シミュレーションを用いたフェムト秒レーザーアブレーションに関する研究

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分子動力学シミュレーションから得られた結果と，軟X線レーザー干渉計測によって得られた実験データを相互に活用することにより，フェムト秒レーザーによるアブレーションにおける基礎的な構造変化に関する研究行う．
マイクロ波ロケット飛行実証実験

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マイクロ波伝播からプラズマ生成，そして衝撃波による推力生成までを一貫して解析可能な数値計算コードを開発し，マイクロ波ロケットの推力予測と高効率化に向けた指針を得る．
数値シミュレーションを用いた高温・高Re数条件下での熱流束値の解析委託

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大気圏再突入カプセル周りの数値シミュレーションを実施し、高温衝撃風洞試験データと比較・検証を行うことで、数値シミュレーション物理モデルの検証を行い、高温衝撃風洞の試験精度を左右する物理現象(異常高熱流束現象)の原因解明を狙う。
火星大気突入時における火星ダストの探査機への影響把握に関する研究

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微小異物衝突及び再突入熱空力と複合材損傷の連成解析，複合材のダスト耐性の把握，火星探査機における対応策の検討
実験室宇宙プラズマの輻射流体シミュレーション

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輻射流体コードを用いてレーザー生成プラズマ流の予測を行い，宇宙物理学に関連した衝撃波不安定性や無衝突衝撃波，ジェット伝播実験の提案および解析を行う．また，実験解析を通して輻射流体コードの高度化を図る．
大気圧プラズマジェットによる歯根管内殺菌消毒治療の開発

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プラズマにより生成されるラジカルの殺菌メカニズム及び効果の物理化学的解明のための液中ラジカルの拡散シミュレーション
無衝突衝撃波生成実験に関するグローバルシミュレーション

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レーザー生成プラズマを用いて、レーザー生成プラズマと物質との相互作用、複数ターゲットからのレーザー生成プラズマ同士の相互作用に関するグローバル流体シミュレーション、及び宇宙ジェット伝播模擬実験など実験室宇宙物理に対する、実験提案、実験データ解析を行う。
非等方・非定常輻射場と流れ場の結合計算に関する研究

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高温気体やプラズマの流れ場においては，媒質から発生する輻射によるエネルギー輸送が流れ場の挙動に大きく影響する場合がある．このような流れ場を数値的に解析しようとする場合，輻射輸送方程式をなんらかの形で流体の支配方程式と結合する必要がある．レーザーアブレーション等の密度の変化が急激な流れ場では，輻射場は非等方性を残しながらも，場所によっては輸送における拡散的な速度が流れ場の速度と同等程度になる場合がある．このような場合，光学的厚さに対する2つの極限のどちらかでは現象が適切に記述できず，2つの極限を滑らかにつなぐ方法が必要となってくる．本研究では，輻射モーメント方程式の解法にエディントンテンソルを非局所的に決定する手法を導入することで，輻射流体計算に適した非等方性を考慮に入れた新しい計算手法を検討した．そして，比較的単純な条件下でテスト計算を行って従来の手法と比較し，その妥当性について調べた．
輻射流体計算手法の高度化に関する研究

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輻射流体計算手法の高度化に関する研究
X線レーザーにおけるプラズマ媒質の数値シミュレーションによる研究

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X線レーザーにおけるプラズマ媒質の数値シミュレーションによる研究
レーザー核融合における輻射流体シミュレーションに関する研究

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レーザー核融合における輻射流体シミュレーションに関する研究

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