顔写真

アベ ヨシアキ
阿部 圭晃
Yoshiaki Abe
所属
流体科学研究所 附属統合流動科学国際研究教育センター マルチフィジックスデザイン研究分野
職名
助教
学位
  • 博士(工学)(東京大学)

  • 修士(工学)(東京大学)

e-Rad 研究者番号
40785010

経歴 3

  • 2016年11月 ~ 2018年9月
    Imperial College London Department of Aeronautics Research Associate

  • 2016年4月 ~ 2016年11月
    日本学術振興会・特別研究員 東京工業大学 PD

  • 2013年4月 ~ 2016年3月
    日本学術振興会・特別研究員 東京大学 DC

学歴 3

  • 東京大学大学院 工学系研究科 航空宇宙工学専攻 博士課程

    2013年4月 ~ 2016年3月

  • 東京大学大学院 工学系研究科 航空宇宙工学専攻 修士課程

    2011年4月 ~ 2013年3月

  • 京都大学 工学部 物理工学科

    2007年4月 ~ 2011年3月

委員歴 4

  • 日本機械学会 流体工学部門講習会幹事

    2022年4月 ~ 継続中

  • 日本航空宇宙学会 北部支部幹事

    2022年3月 ~ 継続中

  • 日本機械学会 LAJ委員会

    2021年4月 ~ 継続中

  • 日本流体力学会 第35回数値流体力学シンポジウム実行委員

    2021年1月 ~ 2021年12月

所属学協会 4

  • 日本複合材料学会

  • 日本流体力学会

  • 日本機械学会

  • 日本航空宇宙学会

研究キーワード 3

  • 航空宇宙工学

  • 数値流体力学

  • 流体力学

研究分野 3

  • 情報通信 / 計算科学 /

  • フロンティア(航空・船舶) / 航空宇宙工学 /

  • ものづくり技術(機械・電気電子・化学工学) / 流体工学 /

受賞 11

  1. 文部科学大臣表彰 若手科学者賞

    2022年4月 文部科学省

  2. 奨励賞(研究)

    2022年2月 一般社団法人 日本機械学会 圧縮性流体の離散保存性を満たす高精度解析手法とその応用

  3. 第8回東北大学若手アンサンブルワークショップポスター賞

    2021年12月 東北大学若手アンサンブルプロジェクト ガスジェット浮遊法による熱物性測定技術の高度化

  4. 第53回流体力学講演会/第39回航空宇宙数値シミュレーション技術シンポジウム 流体力学部門 最優秀賞

    2021年6月 一般社団法人 日本航空宇宙学会 ガスジェット浮遊法における高温球の浮遊安定性

  5. 工学系研究科長賞(研究・博士課程)

    2016年3月 東京大学

  6. 優秀講演賞

    2015年7月 第47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

  7. ベストCFDグラフィックスアワード

    2013年12月 第27回数値流体力学シンポジウム

  8. 優秀学生講演賞

    2013年7月 第41回可視化情報シンポジウム

  9. 優秀学生講演賞

    2013年4月 第44期航空宇宙学会年会講演会

  10. 工学系研究科長賞(研究・修士課程)

    2013年3月 東京大学

  11. 優秀講演賞

    2012年7月 第44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

︎全件表示 ︎最初の5件までを表示

論文 43

  1. Comparison of Separation Control Mechanisms for Synthetic Jet and Plasma Actuators

    Yoshiaki Abe, Taku Nonomura, Makoto Sato, Hikaru Aono, Kozo Fujii

    Actuators 12 (8) 2023年8月

    DOI: 10.3390/act12080322  

    eISSN:2076-0825

    詳細を見る 詳細を閉じる

    This study numerically investigated the mechanisms of separation control using a synthetic jet (SJ) and plasma actuator (PA) around an NACA0015 airfoil at the chord Reynolds number of 63,000. Both SJ and PA were installed on the leading edge with the same order of input momentum ((Formula presented.) – (Formula presented.)) and the same actuation frequencies in (Formula presented.) –30. The momentum coefficient (Formula presented.) is defined as the normalized momentum introduced from the SJ or the PA, and (Formula presented.) stands for the actuation frequency normalized by the chord length and uniform velocity. A number of large-eddy simulations (LES) were conducted for the SJ and the PA, and the mechanisms were clarified in terms of the exchange of chordwise momentum with Reynolds shear stress and coherent vortex structures. First, four main differences in the induced flows of the SJ and the PA were clarified as follows: (A) wall-tangential velocity; (B) three-dimensional flow structures; (C) spatial locality; and (D) temporal fluctuation. Then, a common feature of flow control by the SJ and the PA was revealed: a lift-to-drag ratio was found to be better recovered in (Formula presented.) –20 than in other frequencies. Although there were differences in the induced flows, the phase decomposition of the flow fields identified common mechanisms that the turbulent component of the Reynolds shear stress mainly contributes to the exchange of the chordwise (streamwise) momentum; and the turbulent vortices are convected over the airfoil surface by the coherent spanwise vortices in the frequency of (Formula presented.).

  2. Flow instability and momentum exchange in separation control by a synthetic jet

    Yoshiaki Abe, Taku Nonomura, Kozo Fujii

    Physics of Fluids 35 (6) 2023年6月1日

    DOI: 10.1063/5.0148943  

    ISSN:1070-6631

    eISSN:1089-7666

    詳細を見る 詳細を閉じる

    This study investigates a mechanism for controlling separated flows around an airfoil using a synthetic jet (SJ). A large-eddy simulation (LES) was performed for a leading-edge separation flow around an airfoil at the chord Reynolds number of 63 000 and the angle of attack of 12°. The present LES resolves a turbulent structure inside a deforming SJ cavity with a deforming grid. An optimal actuation-frequency band is identified between the normalized frequencies of F + = 6.0 and 20, which suppresses the separation and drastically improves the lift-to-drag ratio. In the controlled flows, the laminar separation bubble near the leading edge periodically releases multiple spanwise-uniform vortex structures, which diffuse and merge to generate a single coherent vortex in the period of F+. Such a coherent vortex plays a significant role in exchanging a chordwise momentum between a near-wall surface and the freestream away from the wall. It also entrains smaller turbulent vortices and eventually enhances the turbulent component of the Reynolds stress throughout the suction surface. Linear stability theory (LST) was subsequently compared with the LES result, which clarifies the applicability of the LST to the controlled flows. In the optimal F+ regime, both linear and nonlinear modes are excited in a well-balanced manner, where the first mode is associated with the Kelvin-Helmholtz instability and contributes to a quick and smooth turbulent transition, while the second mode shows a frequency lower than that of the linear mode and encourages a formation of the coherent vortex structure that eventually entrains smaller turbulent vortices.

  3. Model position sensing method for low fineness ratio models in a magnetic suspension and balance system

    Chiharu Inomata, Masahide Kuwata, Sho Yokota, Yoshiaki Abe, Hideo Sawada, Shigeru Obayashi, Keisuke Asai, Taku Nonomura

    Review of Scientific Instruments 94 (2) 025102-025102 2023年2月1日

    出版者・発行元:AIP Publishing

    DOI: 10.1063/5.0113806  

    ISSN:0034-6748

    eISSN:1089-7623

    詳細を見る 詳細を閉じる

    A new model-position-sensing method for the levitation of models with a low fineness ratio (ratio of the longitudinal length to the diameter) in a magnetic suspension and balance system (MSBS) is proposed. MSBS is an ideal model-support device for wind-tunnel testing, which enables the study of flow fields around blunt bodies without flow disturbances introduced by mechanical support devices, with the aerodynamic forces determined from the magnetic forces using a pre-calibrated relationship. The new method allows wind tunnel experiments without mechanical supports with a low fineness ratio model. This method adopts two line sensors placed parallel to the central axis of the model image and measures the position with a resolution finer than 0.06 mm or deg even for thin model geometries. In addition, measurement errors were reduced by correcting a second-order term in the depth direction of the camera. A low fineness ratio circular cylinder model was levitated following sensor calibration. The model was supported in conditions with and without freestream flow. This position measurement method was also applied to a reentry capsule model. The model was levitated while keeping its position and attitude stabilized near the origin.

  4. Long-term two-dimensional analysis of the flow field around a hovering flapping flat-plate wing

    Tomoki YAMAZAKI, Yoshiaki ABE, Tomonaga OKABE

    Journal of Fluid Science and Technology 18 (2) JFST0026-JFST0026 2023年

    出版者・発行元:Japan Society of Mechanical Engineers

    DOI: 10.1299/jfst.2023jfst0026  

    eISSN:1880-5558

  5. 複合材航空機主翼の静的空力弾性解析に向けた完全分離解法の提案 査読有り

    阿部 圭晃, 山﨑 智基, 伊達 周吾, 竹内 稔, 庄司 伊織, 大林 茂, 岡部 朋永

    日本複合材料学会誌 48 (6) 2022年10月

  6. Generalized coordinate smoothed particle hydrodynamics with an overset method in total Lagrangian formulation

    Huachao Deng, Yoshiaki Kawagoe, Yoshiaki Abe, Kenjiro Terada, Tomonaga Okabe

    International Journal for Numerical Methods in Engineering 2022年6月3日

    出版者・発行元:Wiley

    DOI: 10.1002/nme.7043  

    ISSN:0029-5981

    eISSN:1097-0207

  7. Effects of fiber properties on aerodynamic performance and structural sizing of composite aircraft wings

    Shugo Date, Yoshiaki Abe, Tomonaga Okabe

    Aerospace Science and Technology 124 107565-107565 2022年5月

    出版者・発行元:Elsevier BV

    DOI: 10.1016/j.ast.2022.107565  

    ISSN:1270-9638

  8. High-order accurate direct numerical simulation of flow over a MTU-T161 low pressure turbine blade 査読有り

    A.S. Iyer, Y. Abe, B.C. Vermeire, P. Bechlars, R.D. Baier, A. Jameson, F.D. Witherden, P.E. Vincent

    Computers & Fluids 226 104989-104989 2021年8月

    出版者・発行元:Elsevier BV

    DOI: 10.1016/j.compfluid.2021.104989  

    ISSN:0045-7930

  9. Computational study on aeroacoustic fields of a transitional supersonic jet

    Taku Nonomura, Yuta Ozawa, Yoshiaki Abe, Kozo Fujii

    Journal of the Acoustical Society of America 149 (6) 4484-4502 2021年6月1日

    DOI: 10.1121/10.0005313  

    ISSN:0001-4966

    eISSN:1520-8524

    詳細を見る 詳細を閉じる

    Aeroacoustic fields of a supersonic free jet at the Mach and Reynolds numbers of 2.1 and 70 000, respectively, of the transitional conditions are computationally investigated by large-eddy simulations. The supersonic transitional jets of different shear layer thicknesses without disturbances and those of the fixed shear layer thickness with disturbances are computationally investigated, and the effects of the shear layer thickness and the disturbance are discussed. The position of the transition and the turbulence intensity in the vicinity of the transition are clearly affected by those parameters. The turbulent fluctuation along the shear layer and the resulting intensity of the generated Mach waves are substantially attenuated by decreasing the shear layer thickness or adding the disturbance. A 5 dB increase in the sound pressure level is observed. This relatively lower increment in the sound pressure level compared with the 10-20 dB increase in the subsonic jet case is discussed as being due to the transition process promoted by the spiral mode in the supersonic jet case, unlike the axisymmetric case in the subsonic jet case. This point is confirmed by the linear stability analysis, the proper orthogonal decomposition analysis, and the visualization of vortex structures in the transition region.

  10. Boundary variation diminishing algorithm for high‐order local polynomial‐based schemes 査読有り

    Yoshiaki Abe, Ziyao Sun, Feng Xiao

    International Journal for Numerical Methods in Fluids 93 (3) 892-907 2021年3月

    出版者・発行元:Wiley

    DOI: 10.1002/fld.4899  

    ISSN:0271-2091

    eISSN:1097-0363

    詳細を見る 詳細を閉じる

    A novel approach for selecting appropriate reconstructions is implemented to the hyperbolic conservation laws in the high-order local polynomial-based framework, for example, the discontinuous Galerkin (DG) and flux reconstruction (FR) schemes. The high-order polynomial approximation generally fails to correctly capture a strong discontinuity inside a cell due to the Gibbs phenomenon, which is replaced by more stable approximation on the basis of a troubled-cell indicator such as that used with the total variation bounded (TVB) limiter. This paper examines the applicability of a new algorithm, so-called boundary variation diminishing (BVD) reconstruction, to the weighted essentially nonoscillatory methodology in the FR framework including the nodal type DG method. The BVD reconstruction adaptively chooses a proper approximation for the solution function so as to minimize the jump between values at the left and right side of cell boundaries. The results of the BVD algorithm are comparable to those with the conventional TVB limiter in terms of oscillation suppression and numerical dissipation in one-dimensional linear advection and nonlinear system equations, while the TVB limiter performs better in the case with strong discontinuities (the blast wave problem in the Euler equations). Overall, since the present BVD algorithm does not need any ad hoc constant such as the TVB parameter, it could be more reliable than the conventional TVB limiter that is often used in the DG and FR communities for shocks and other discontinuities. The proposed method would lead to a parameter-free robust algorithm for the local polynomial-based high-order schemes.

  11. Flow characteristics around extremely low fineness-ratio circular cylinders 査読有り

    Masahide Kuwata, Yoshiaki Abe, Sho Yokota, Taku Nonomura, Hideo Sawada, Aiko Yakeno, Keisuke Asai, Shigeru Obayashi

    Physical Review Fluids 6 (5) 2021年

    出版者・発行元:American Physical Society (APS)

    DOI: 10.1103/physrevfluids.6.054704  

    eISSN:2469-990X

  12. BVD原理に基づくβ可変THINC法による衝撃波捕獲スキーム 査読有り

    脇村 尋, Deng Xi, 阿部 圭晃, 肖 鋒

    日本航空宇宙学会論文集 69 (3) 113-121 2021年

    出版者・発行元:None

    DOI: 10.2322/jjsass.69.113  

    ISSN:1344-6460

    eISSN:2432-3691

  13. Fluid-structural design analysis for composite aircraft wings with various fiber properties 査読有り

    Shugo DATE, Yoshiaki ABE, Takeki YAMAMOTO, Tomonaga OKABE

    Journal of Fluid Science and Technology 16 (1) JFST0009-JFST0009 2021年

    出版者・発行元:Japan Society of Mechanical Engineers

    DOI: 10.1299/jfst.2021jfst0009  

    ISSN:1880-5558

    eISSN:1880-5558

    詳細を見る 詳細を閉じる

    This study performed an analysis for the fluid-structural design of aircraft wings composed of carbon fiber reinforced plastics (CFRPs). Specifically, the effects of carbon fibers on structural weight were evaluated. A multiscale computational framework was developed for designing CFRP wings so that even those CFRPs can be considered whose mechanical properties are not available as experimentally-measured data, thereby bridging two different scales by the following processes: 1) a microscale analysis for evaluating the mechanical properties (stiffness and strength) of unidirectional CFRP laminates and 2) a macroscale fluid-structural analysis that involves structural sizing of wingbox structures based on the mechanical properties given by the microscale analysis. To this end, five fibers were examined in this study, namely: T300, T700S, T800H, T800S, and T1100G. It was discovered that T1100G exhibited the lightest wingbox structures, followed by T800S, T800H, T700S, T300. This was mainly due to the difference in a thickness of the lower panels, where the thickness was minimized with T1100G among the five fibers, resulting from the tensile failure mode. Meanwhile, the upper panels under compressive load showed two different failure modes, namely: fiber microbuckling and skin buckling. In the region where the fiber microbuckling was dominant, the panel thickness was in order of the stiffness of the fiber, i.e., the panel made with T1100G having the highest stiffness was thicker than that made with T800S, T800H, T700S and T300, and vice versa in the region where the skin buckling was dominant. Based on the microscale analysis, the aforementioned failure mechanisms are consistent with the fact that a quasi-isotropic laminate with the fibers of higher stiffness is more resistant to tensile load and skin buckling but less resistant to compressive load.

  14. Numerical Simulation of Wake Deflection Control around NACA0012 Airfoil Using Active Morphing Flaps 査読有り

    Yoshiaki Abe, Takayuki Konishi, Tomonaga Okabe

    Journal of Flow Control, Measurement & Visualization 08 (03) 121-133 2020年7月

    出版者・発行元:Scientific Research Publishing, Inc.

    DOI: 10.4236/jfcmv.2020.83007  

    ISSN:2329-3322

    eISSN:2329-3330

  15. Separated Flow Control of Small Horizontal-Axis Wind Turbine Blades Using Dielectric Barrier Discharge Plasma Actuators 査読有り

    Hikaru Aono, Hiroaki Fukumoto, Yoshiaki Abe, Makoto Sato, Taku Nonomura, Kozo Fujii

    Energies 13 (5) 1218 2020年3月6日

  16. Drag Coefficients of Circular Cylinders with Fineness Ratios of less than 0.50 measured by 0.1 and 0.3 m Magnetic Suspension and Balance Systems 査読有り

    Masahide Kuwata, Sho Yokota, Hideo Sawada, Yoshiaki Abe, Aiko Yakeno, Taku Nonomura, Keisuke Asai, Shigeru Obayashi

    AIAA Scitech 2020 Forum 1325 2020年1月

    出版者・発行元:None

    DOI: 10.2514/6.2020-1325  

  17. Uncertainty quantification of shock–bubble interaction simulations 査読有り

    J. Jin, X. Deng, Y. Abe, F. Xiao

    Shock Waves 29 (8) 1-14 2019年2月

    DOI: 10.1007/s00193-019-00893-4  

    ISSN:0938-1287

    eISSN:1432-2153

  18. Dominant parameters for maximum velocity induced by body-force models for plasma actuators 査読有り

    Shigetaka Kawai, Thijs Bouwhuis, Yoshiaki Abe, Aiko Yakeno, Taku Nonomura, Hikaru Aono, Akira Oyama, Harry W.M. Hoeijmakers, Kozo Fujii

    Theoretical and Computational Fluid Dynamics 32 (6) 805-820 2018年12月1日

    DOI: 10.1007/s00162-018-0478-9  

    ISSN:0935-4964

    eISSN:1432-2250

    詳細を見る 詳細を閉じる

    © 2018, Springer-Verlag GmbH Germany, part of Springer Nature. This study investigates the relationship between body-force fields and maximum velocity induced in quiescent air for development of a simple body-force model of a plasma actuator. Numerical simulations are conducted with the body force near a wall. The spatial distribution and temporal variation of the body force are a Gaussian distribution and steady actuation, respectively. The dimensional analysis is performed to derive a reference velocity and Reynolds number based on the body-force distribution. It is found that the derived Reynolds number correlates well with the nondimensional maximum velocity induced in quiescent conditions when the center of the Gaussian distribution is fixed at the wall. Additionally, two flow regimes are identified in terms of the Reynolds number. Considering the variation of the center of gravity of force fields, another Reynolds number is defined by introducing a new reference length. The nondimensional maximum velocity is found to be scaled with the latter Reynolds number, i.e., the maximum induced velocity in quiescent conditions is determined from three key parameters of the force field: the total induced momentum per unit time, the height of the center of gravity, and the standard deviation from it. This scaling turns out to be applicable to existing body-force models of the plasma actuator, despite the force distributions different from the Gaussian distribution. Comparisons of velocity profiles with experimental data validate the results and show that the flow induced by a plasma actuator can be simulated with simple force distributions by adjustment of the key body-force parameters.

  19. Unsteady shear layer flow under excited local body-force for flow-separation control in downstream of a two-dimensional hump 査読有り

    A. Yakeno, Y. Abe, S. Kawai, T. Nonomura, K. Fujii

    International Journal of Heat and Fluid Flow 74 15-27 2018年12月

    DOI: 10.1016/j.ijheatfluidflow.2018.08.008  

    ISSN:0142-727X

    詳細を見る 詳細を閉じる

    © 2018 Elsevier Inc. We present a detailed numerical investigation of unsteady shear layer dynamics in downstream under an excited local body force, based on the assumption that a plasma actuator is positioned near the top of a two-dimensional hump for flow-separation control. A local body force works in temporal burst mode, which is homogeneous in the spanwise direction. In our previous report (Yakeno et al., 2015), the most effective frequency to cause early reattachment is fh=0.2, which corresponds to what Hasan (1992) and many other past studies referred to as the step mode. A periodic excitation generates two-dimensional roll vortices and other three-dimensional turbulence between downstream rolls, such as rib structures. These vortex characteristics significantly depend on the excitation frequency. In the study, we discuss these multi-scale turbulence motion separately by considering decomposition of temporal phase-locked periodic statistics of the excitation frequency and non-periodic turbulence fluctuation. At first, we found that non-periodic turbulence kinetic energy due to three-dimensional rib structure increases the most at the optimal frequency fh=0.2, although that frequency corresponds to the time scale that a hump-height vortex grows. It seems that non-periodic turbulence energy growth near separation point correlates with the control performance more than two-dimensional roll vortex increase. We operated linear hydrodynamic stability analysis on a free shear layer and confirmed that periodic phase fluctuation at high frequency grew on the Kelvin-Helmholtz instability. At low-frequency, periodic turbulence fluctuation is not reproduced with the exponential assumption, while its magnitude is large. From those results, we consider that the time and spanwise-averaged non-periodic turbulence energy becomes strong near the separation point the most at fh=0.2 because a hump-height vortex occurs the most times at this frequency, which is associated with a generation of the rib structure around it. Temporal-periodic momentum balance based on the decomposition is also investigated. A difference of terms contribution at high and low frequencies to the term of a pressure gradient in the wall-normal direction is discussed. Finally, we investigated how excitation position affects a total drag around a hump and found that, in some cases, two recirculation regions separately emerge in the downstream of the hump, and thus the control performance is degraded. At fh=0.2, one recirculation occurs regardless of the excitation position, while the most effective position is near the inflection point of the mean velocity of the uncontrolled flow near the wall.

  20. Investigation of maximum velocity induced by body-force fields for simpler modeling of plasma actuators 査読有り

    Shigtaka Kawai, Thijs Bouwhuis, Yoshiaki Abe, Aiko Yakeno, Taku Nonomura, Akira Oyama, Harry W.M. Hoeijmakers, Kozo Fujii

    AIAA Aerospace Sciences Meeting, 2018 (210059) 2018年

    DOI: 10.2514/6.2018-2044  

    詳細を見る 詳細を閉じる

    © 2018, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. The relation between the parameters of the body-force field generated by a plasma actuator and the maximum induced velocity in quiescent air is investigated by expressing the body-force distribution as the Gaussian function of the spatial coordinates. The aim of this study is to identify the dominant parameters for modeling of the body-force distribution. For that purpose, the parametric study using numerical simulations and dimensional analysis are conducted to derive the nondimensional key parameters. It is found that the nondimensional maximum induced velocity is determined by the Reynolds number calculated by three parameters: the total induced momentum per unit time, the height of the center of gravity of the body-force distribution, and the standard deviation from the center of gravity. In addition, the relation for the Gaussian body-force distribution turns out to be applicable to a conventional model, i.e, the Suzen model, even though the shapes of the distribution differ. Thus, we conclude that the three body-force parameters above are the key parameters for the maximum velocity induced by a plasma actuator.

  21. Stable, non-dissipative, and conservative flux-reconstruction schemes in split forms 査読有り

    Abe, Y., Morinaka, I., Haga, T., Nonomura, T., Shibata, H., Miyaji, K.

    Journal of Computational Physics 353 193-227 2018年

    DOI: 10.1016/j.jcp.2017.10.007  

    ISSN:0021-9991

  22. Spanwise modulation effects of local body force on downstream turbulence growth around two-dimensional hump 査読有り

    A. Yakeno, Y. Abe, S. Kawai, T. Nonomura, K. Fujii

    INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW 63 108-118 2017年2月

    出版者・発行元:ELSEVIER SCIENCE INC

    DOI: 10.1016/j.ijheatfluidflow.2016.11.012  

    ISSN:0142-727X

    eISSN:1879-2278

    詳細を見る 詳細を閉じる

    Flow characteristics under flow-separation control by the spanwise-modulated body force of a plasma actuator around a two-dimensional hump are numerically investigated. When the Reynolds number is set to Re-h =16000, the incoming flow contains much disturbance and a near-wall streak structure appears around the hump. The local body force induces stable streamwise velocity to form a streak-like profile artificially. Under the forcing, turbulence fluctuations increase downstream, with resulting in early flow reattachment. These changes alter the momentum balance around the hump. Particularly, the wall-normal pressure gradient and velocity fluctuation terms in the momentum equation are modified. This somewhat suggests a relation between increases in wall-normal gradient terms and the flow reattachment profile under the control. In addition, the turbulence growth depends on the spanwise modulation wavelength of the forcing. The most effective wavelength among those tested here is lambda(z) = 0.08, normalized by the hump height, which is 1 = 150 in local viscous wall units. This viscous scale corresponds to that of a streak structure appearing around a two-dimensional hump. (C) 2016 Elsevier Inc. All rights reserved.

  23. Conservative high-order flux-reconstruction schemes on moving and deforming grids 査読有り

    Yoshiaki Abe, Takanori Haga, Taku Nonomura, Kozo Fujii

    COMPUTERS & FLUIDS 139 2-16 2016年11月

    出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD

    DOI: 10.1016/j.compfluid.2016.03.024  

    ISSN:0045-7930

    eISSN:1879-0747

    詳細を見る 詳細を閉じる

    An appropriate procedure to construct symmetric conservative metrics is presented for the high-order conservative flux-reconstruction scheme on three-dimensionally moving and deforming grids. The present framework enables direct discretization of the strong conservation form of governing equations without any errors in the freestream preservation and global conservation properties. We demonstrate that a straightforward implementation of the symmetric conservative metrics often fails to construct metric polynomials having the same order as a solution polynomial, which severely degrades the numerical accuracy. On the other hand, the symmetric conservative metrics constructed using an appropriate procedure can preserve the freestream solution regardless of the order of shape functions. Moreover, a convecting vortex is more accurately computed on deforming grids. The global conservation property is also demonstrated numerically for the convecting vortex on deforming grids. (C) 2016 The Authors. Published by Elsevier Ltd.

  24. Mechanisms for laminar separated-flow control using dielectric-barrier-discharge plasma actuator at low Reynolds number 査読有り

    Makoto Sato, Taku Nonomura, Koichi Okada, Kengo Asada, Hikaru Aono, Aiko Yakeno, Yoshiaki Abe, Kozo Fujii

    PHYSICS OF FLUIDS 27 (11) 2015年11月

    出版者・発行元:AMER INST PHYSICS

    DOI: 10.1063/1.4935357  

    ISSN:1070-6631

    eISSN:1089-7666

    詳細を見る 詳細を閉じる

    Large-eddy simulations have been conducted to investigate the mechanisms of separated-flow control using a dielectric barrier discharge plasma actuator at a low Reynolds number. In the present study, the mechanisms are classified according to the means of momentum injection to the boundary layer. The separated flow around the NACA 0015 airfoil at a Reynolds number of 63 000 is used as the base flow for separation control. Both normal and burst mode actuations are adopted in separation control. The burst frequency non-dimensionalized by the freestream velocity and the chord length (F+) is varied from 0.25 to 25, and we discuss the control mechanism through the comparison of the aerodynamic performance and controlled flow-fields in each normal and burst case. Lift and drag coefficients are significantly improved for the cases of F+ = 1, 5, and 15 due to flow reattachment associated with a laminar-separation bubble. Frequency and linear stability analyses indicate that the F+ = 5 and 15 cases effectively excite the natural unstable frequency at the separated shear layer, which is caused by the Kelvin-Helmholtz instability. This excitation results in earlier flow reattachment due to earlier turbulent transition. Furthermore, the Reynolds stress decomposition is conducted in order to identify the means of momentum entrainment resulted from large-scale spanwise vortical structure or small-scale turbulent vortices. For the cases with flow reattachment, the large-scale spanwise vortices, which shed from the separated shear layer through plasma actuation, significantly increase the periodic component of the Reynolds stress near the leading edge. These large-scale vortices collapse to small-scale turbulent vortices, and the turbulent component of the Reynolds stress increases around the large-scale vortices. In these cases, although the combination of momentum entrainment by both Reynolds stress components results in flow reattachment, the dominant component is identified as the turbulent component. This indicates that one of the effective control mechanisms for laminar separation is momentum entrainment by turbulent vortices through turbulent transition. (C) 2015 AIP Publishing LLC.

  25. The effects of actuation frequency on the separation control over an airfoil using a synthetic jet 査読有り

    Y. Abe, K. Okada, T. Nonomura, K. Fujii

    Progress in Flight Physics 7 (7) 147-168 2015年6月

    DOI: 10.1051/eucass/201507147  

  26. Effects of interval of spanwise-modulated local forcing on mechanisms of flow separation control 査読有り

    A. Yakeno, Y. Abe, S. Kawai, T. Nonomura, K. Fujii

    Proceedings of the International Symposium on Turbulence, Heat and Mass Transfer 0 719-722 2015年

    eISSN:2377-2816

    詳細を見る 詳細を閉じる

    © 2015 Begell House, Inc. We investigate the effects of the spanwise-modulation interval of local forcing on the mechanisms of flow separation control around a two-dimensional hump. It is shown that a spanwise modulation of y = 0:08 maximally increases the three-dimensional velocity fluctuations and leads to reattachment. Static local-forcing is assumed to promote the lift-up effects of the bypass transition of the streaks. Perturbation growth might be dependent on the spanwise interval of the forcing.

  27. Spatial growth of the spanwise disturbance induced by a synthetic jet on separation control over an airfoil 査読有り

    Yoshiaki Abe, Taku Nonomura, Kozo Fujii

    53rd AIAA Aerospace Sciences Meeting 2015年

    DOI: 10.2514/6.2015-1057  

    詳細を見る 詳細を閉じる

    © 2015 by Yoshiaki Abe, Taku Nonomura, Kozo Fujii. The spatial growth of the spanwise disturbance induced by a synthetic jet is investigated on separated-flow control around NACA0015 (Re=63; 000 and AOA = 12: 0°) using a large-eddy simulation. The synthetic jet is installed at a leading edge which is numerically modeled by a three-dimensional deforming cavity: “Cavity model”; and an artificial jet profile for a boundary condition: “Bc model”. The jet profile of the Bc model is assumed to be sinusoidally oscillated in a spanwise direction with a wave number from kyin=2π = 0 to 95. In the Cavity model case, the modes around ky=2π= 20 to 30 are selectively amplified near the synthetic jet, which remains also in the turbulent boundary layer. In the Bc model cases, the most quick turbulent transition occurs in the case with kyin=2π = 30, where the coherent spanwise mode strongly remains in the turbulent boundary layer although its aerodynamic performance is not best. This result indicates that in the present condition, the spanwise disturbance of the jet profile does not always contribute to the higher aerodynamic performance even if it provides smooth and quick turbulent transition.

  28. Fully-conservative high-order FR scheme on moving and deforming grids 査読有り

    Yoshiaki Abe, Takanori Haga, Taku Nonomura, Kozo Fujii

    22nd AIAA Computational Fluid Dynamics Conference 2015年

    DOI: 10.2514/6.2015-2745  

    詳細を見る 詳細を閉じる

    © 2015, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved. The appropriate procedure for constructing the symmetric conservative metric is presented with which both of the freestream preservation and global conservation proper- ties are satisfied in the high-order conservative flux-reconstruction scheme on a threedimensionally-curved moving and deforming grid. A freestream preservation test is con- ducted, where the freestream preservation and global conservation properties were demonstrated. The symmetric conservative metric constructed by the appropriate procedure preserves the freestream with regardless of the order of shape functions, while other metrics cannot always preserve the freestream. Also a convecting vortex is computed on three-dimensional wavy grids for Euler equations, and the vortex is better preserved when the symmetric conservative metric is appropriately constructed, while it is not when the order of the interpolation polynomial for the metrics is smaller than that for the solution polynomial.

  29. On the freestream preservation of high-order conservative flux-reconstruction schemes 査読有り

    Yoshiaki Abe, Takanori Haga, Taku Nonomura, Kozo Fujii

    JOURNAL OF COMPUTATIONAL PHYSICS 281 28-54 2015年1月

    出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE

    DOI: 10.1016/j.jcp.2014.10.011  

    ISSN:0021-9991

    eISSN:1090-2716

    詳細を見る 詳細を閉じる

    The appropriate procedure for constructing the symmetric conservative metric is presented with which both thefreestream preservation and global conservation properties are satisfied in the high-order conservative flux-reconstruction scheme on a three-dimensional stationary-curvilinear grid. A freestream preservation test is conducted, and the symmetric conservative metric constructed by the appropriate procedure preserves the freestream regardlessof the order of shape functions, while other metrics cannot always preserve the freestream. Also a convecting vortex is computed on three-dimensional wavy grids, and the formal order of accuracy is achieved when the symmetric conservative metric is appropriately constructed, while it is not when they are inappropriately constructed. In addition, although the sufficient condition for the freestream preservation with the nonconservative (cross product form) metric was reported in the previous study to be that the order of solution polynomial has to be greater than or equal to the twice of the order of a shape function, a special case is newly found in the present study: when the Radau polynomial is used for the correction function, the freestream is preserved even if the solution order is lower than the known condition. Using the properties of Legendre polynomials, the mechanism for this special case is analytically explained, considering the cancellation of aliasing errors. (C) 2014 Elsevier Inc. All rights reserved.

  30. A new technique for freestream preservation of finite-difference WENO on curvilinear grid 査読有り

    Taku Nonomura, Daiki Terakado, Yoshiaki Abe, Kozo Fujii

    COMPUTERS & FLUIDS 107 242-255 2015年1月

    出版者・発行元:PERGAMON-ELSEVIER SCIENCE LTD

    DOI: 10.1016/j.compfluid.2014.09.025  

    ISSN:0045-7930

    eISSN:1879-0747

    詳細を見る 詳細を閉じる

    A new technique for a finite-difference weighted essentially nonoscillatory scheme (WENO) on curvilinear grids to preserve freestream is introduced. This technique first divides the standard finite-difference WENO into two parts: (I) a consistent central difference part and (2) a numerical dissipation part. For the consistent central difference part, the conservative metric technique is directly adopted. For the numerical dissipation part, it is proposed that the metric term should be frozen for constructing the upwinding flux. This treatment only affects the numerical dissipation part, and the order of accuracy is maintained. With this technique, the freestream is perfectly preserved, and the flow fields are better resolved on wavy and random grids. (C) 2014 The Authors. Published by Elsevier Ltd.

  31. Freestream preservation on a high-order conservative Fr scheme 査読有り

    Yoshiaki Abe, Takanori Haga, Taku Nonomura, Kozo Fujii

    11th World Congress on Computational Mechanics, WCCM 2014, 5th European Conference on Computational Mechanics, ECCM 2014 and 6th European Conference on Computational Fluid Dynamics, ECFD 2014 5637-5650 2014年7月1日

    詳細を見る 詳細を閉じる

    The appropriate procedure for constructing symmetric conservative metrics is presented with which both of the freestream preservation and global conservation properties are satisfied in the high-order conservative flux-reconstruction scheme on a three-dimensional stationary-curvilinear grid. A freestream preservation test is conducted, and the symmetric conservative metrics constructed by the appropriate procedure preserve the freestream with regardless of the order of shape functions, while other metrics cannot always preserve the freestream. Also a convecting vortex is computed on three-dimensional wavy grids, and the formal order of accuracy is achieved when the symmetric conservative metrics are appropriately constructed, while it is not when they are inappropriately constructed.

  32. Geometric interpretations and spatial symmetry property of metrics in the conservative form for high-order finite-difference schemes on moving and deforming grids 査読有り

    Yoshiaki Abe, Taku Nonomura, Nobuyuki Iizuka, Kozo Fujii

    JOURNAL OF COMPUTATIONAL PHYSICS 260 163-203 2014年3月

    出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE

    DOI: 10.1016/j.jcp.2013.12.019  

    ISSN:0021-9991

    eISSN:1090-2716

    詳細を見る 詳細を閉じる

    The role of a geometric conservation law (GCL) on a finite-difference scheme is revisited for conservation laws, and the conservative forms of coordinate-transformation metrics are introduced in general dimensions. The sufficient condition of a linear high-order finite-difference scheme is arranged in detail, for which the discretized conservative coordinate-transformation metrics and Jacobian satisfy the GCL identities on three-dimensional moving and deforming grids. Subsequently, the geometric interpretation of the metrics and Jacobian discretized by a linear high-order finite-difference scheme is discussed, and only the symmetric conservative forms of the discretized metrics and Jacobian are shown to have the appropriate geometric structures. The symmetric and asymmetric conservative forms of the metrics and Jacobian are examined by the computation of an inviscid compressible fluid on highly-skewed stationary and deforming grids using sixth-order compact and fourth-order explicit central-difference schemes, respectively. The resolution of the isentropic vortex and the robustness of the computation are improved by employing symmetric conservative forms on the coordinate-transformation metrics and Jacobian that have an appropriate geometry background. An integrated conservation of conservative quantities is also attained on the deforming grid when symmetric conservative forms are adopted to the time metrics and Jacobian. (C) 2013 Elsevier Inc. All rights reserved.

  33. 乱流遷移する超音速ジェットの線形安定解析とLES 査読有り

    野々村拓, 阿部圭晃, 渡辺毅, 藤井孝藏

    第92期日本機械学会流体工学部門講演会講演論文集 1403-1403 2014年

  34. Flow Control using a DBD Plasma Actuator for Horizontal-axis Wind Turbine Blades of Simple Experimental Model 査読有り

    Hikaru Aono, Yoshiaki Abe, Makoto Sato, Aiko Yakeno, Koichi Okada, Taku Nonomura, Kozo Fujii

    11th World Congress on Computational Mechanics, WCCM 2014, 5th European Conference on Computational Mechanics, ECCM 2014 and 6th European Conference on Computational Fluid Dynamics, ECFD 2014 5193-5204 2014年

    出版者・発行元:None

  35. A new technique for finite difference WENO with geometric conservation law 査読有り

    Taku Nonomura, Daiki Terakado, Yoshiaki Abe, Kozo Fujii

    21st AIAA Computational Fluid Dynamics Conference 2013年

    詳細を見る 詳細を閉じる

    A new technique for a finite-difference weighted essentially nonoscillatory scheme (WENO) to satisfy the geometric conservation law on an arbitrary grid system is introduced. This new technique first divides the finite difference WENO into two parts: 1) a consistent central difference part and 2) a numerical dissipation part. For the consistent central difference part, the conservative metric technique is straightforwardly adapted. For the numerical dissipation part, it is proposed that the metric term is frozen for constructing the upwinding flux. This treatment only affects the numerical dissipation part, and the order of accuracy is maintained. With this technique, the freestream is perfectly preserved, and also the flow fields are better resolved on wavy and random grids.

  36. 回転するタイヤ周りに発生する空力音の数値解析 査読有り

    阿部圭晃, 野々村拓, 近藤勝俊, 飯田大貴, 渡辺毅, 池田俊之, 小石正隆, 山本誠, 藤井孝藏

    第27回数値流体力学シンポジウム講演論文集 A10-2-A10-2 2013年

  37. Control mechanism of plasma actuator for separated flow around NACA0015 at Reynolds number 63,000 -separation bubble related mechanisms- 査読有り

    Taku Nonomura, Hikaru Aono, Makoto Sato, Aiko Yakeno, Koichi Okada, Yoshiaki Abe, Kozo Fujii

    51st AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 2013 2013年

    詳細を見る 詳細を閉じる

    In this paper, the mechanisms of control of separated flow around NACA0015 of angle of attach 12 degree at Reynolds number 63,000 using plasma actuator are classified and discussed. A series of large-eddy simulations using compact scheme is conducted, and results are discussed. Especially, the flow control mechanism related to the separation bubble is discussed for the cases with the burst actuation of plasma actuator at nondimensinal burst wave frequency of 1 and 6 based on chord length and freestream. The averaged flow fields show that the case with the nondimensional burst wave frequency of 6 has earlier and smooth transition and it uses the turbulent mixing effectively. This earlier transition is because the actuation with the nondimensional burst wave frequency of 6 effectively excites the Kelvin-Helmholz instability. On the other hand, though the phase averaged flow fields illustrate that the case with nondimensional frequency of 1 uses the mixing by the large vortex more than F+ = 6, the periodic components of Reynolds stress is much smaller than turbulent components of that. This result show that, at least in terms of Reynolds stress, the turbulent mixing is more important for flow control in this situation. © 2013 by Taku Nonomura, Makoto Sato, Hikaru Aono, Aiko Yakeno, Koichi Okada, Yosihaki Ave, Kozo Fujii.

  38. Massive parametric study by LES on separated- flow control around airfoil using DBD plasma actuator at Reynolds number 63,000 査読有り

    Makoto Sato, Koichi Okada, Taku Nonomura, Hikaru Aono, Aiko Yakeno, Kengo Asada, Yoshiaki Abe, Kozo Fujii

    43rd Fluid Dynamics Conference 2013年

    詳細を見る 詳細を閉じる

    A massive number of large-eddy simulations of the separated flow over NACA0015 airfoil, which are controlled by a DBD plasma actuator, are conducted. Reynolds number based on chord length is 63,000 and the angle of attack is from 12 to 18, which are stall angle in present flow condition. The position and operation conditions of a DBD plasma actuator, (e.g. the burst frequency, the degree of induced flow and the burst ratio of actuation) are varied as parameters. It is clarified that the most effective position of the actuator to suppress the separation is vicinity of the separation point. The most effective burst frequency of burst wave to improve the lift-drag ratio is F+ ≈ 5. In the cases of these optimal position and burst frequency, the energy consumption by actuation can be reduced so much. The promotion of turbulent transition is closely related to the control of separation. The simple analyses of turbulent kinetic energy distributions clarify that the cases with quick turbulent transition over airfoil have better aerodynamic performance. In addition, other mechanisms of the separation control are also shown for each angle of attack, and the effect of control are classified in terms of the improvement of aerodynamic performances.

  39. Significance of three-dimensional unsteady flows inside the cavity on separated- flow control around an NACA0015 using a synthetic jet 査読有り

    Yoshiaki Abe, Koichi Okada, Makoto Sato, Taku Nonomura, Kozo Fujii

    43rd Fluid Dynamics Conference 2013年

    DOI: 10.2514/6.2013-2748  

    詳細を見る 詳細を閉じる

    The simulation of a separation control using a synthetic jet around an NACA0015 airfoil at Reynolds number 63,000 is conducted by a large-eddy simulation (LES) with a compact difference scheme. The synthetic jet is installed at a leading edge and actuated with nondimensional frequencies F+ = 1:0 and 6:0, which is numerically modeled by a threedimensional deforming cavity: "Cavity model" and a two-dimensional boundary condition on the airfoil: " Bc model". The aerodynamic coefficients of the controlled flows are similarly recovered from those of the separated flow using both of the Cavity and Bc model. However, the time-averaged values and flow fields are significantly different in two models, and the use of Bc model on the three-dimensional analysis is not proper. In the case with F+ = 6, a turbulent transition near the leading edge occurs much earlier with the Cavity model than the Bc model. This result indicates that the spanwise disturbance from the cavity to the separated shear layer should be carefully considered when three-dimensional unsteady analysis is conducted by LES.

  40. Conservative metric evaluation for high-order finite difference schemes with the GCL identities on moving and deforming grids 査読有り

    Yoshiaki Abe, Nobuyuki Iizuka, Taku Nonomura, Kozo Fujii

    JOURNAL OF COMPUTATIONAL PHYSICS 232 (1) 14-21 2013年1月

    出版者・発行元:ACADEMIC PRESS INC ELSEVIER SCIENCE

    DOI: 10.1016/j.jcp.2012.08.031  

    ISSN:0021-9991

  41. Symmetric-conservative metric evaluations for higher-order finite difference scheme with the GCL identities on three-dimensional moving and deforming mesh 査読有り

    Y. Abe, N. Iizuka, T. Nonomura, K. Fujii

    7th International Conference on Computational Fluid Dynamics, ICCFD 2012 2012年

    詳細を見る 詳細を閉じる

    © 2012 7th International Conference on Computational Fluid Dynamics, ICCFD 2012. All rights reserved. New conservative forms are introduced for time metrics and the Jacobian, which satisfy the geometric conservation law (:GCL) identity even when higher-order spatial discretization is employed for the moving and deforming meshes. The conservative quantities are ensured to keep constant for three-dimensional moving and deforming meshes with use of these new forms for the computation of the uniform flow. In addition, one of the new forms has spatial symmetry property, and some tests indicate the significance of the spatial symmetry in the expression of time metrics and the Jacobian.

  42. On the discretization of spatial metrics satisfying the GCL identities 査読有り

    Y. Abe, T. Nonomura, N. Iizuka, K. Fujii

    ECCOMAS 2012 - European Congress on Computational Methods in Applied Sciences and Engineering, e-Book Full Papers 3575-3594 2012年

    詳細を見る 詳細を閉じる

    In this research, the spatial metrics used in the finite difference scheme for curvilinear coordinate system are discussed from the viewpoint of geometric interpretation. We summarized all the evaluation technique for second-order metrics proposed in the previous studies, and explain their geometric interpretation if they have appropriate geometries. Adoptingthe regular second-order finite difference scheme, only the symmetric conservative formulation has the appropriate geometry in the viewpoint of finite volume scheme. This form straightforwardly extended to the high order scheme, having appropriate geometry interpretations. This form improves the robustness of the high-order computation on the highly skewed grids compared with the asymmetric conservative formulation which is often used in the fluidic computation.

  43. STAGNATION-POINT FLOW OF A RAREFIED GAS IMPINGING OBLIQUELY ON A PLANE WALL 査読有り

    Kazuo Aoki, Yoshiaki Abe

    KINETIC AND RELATED MODELS 4 (4) 935-954 2011年12月

    出版者・発行元:AMER INST MATHEMATICAL SCIENCES

    DOI: 10.3934/krm.2011.4.935  

    ISSN:1937-5093

    詳細を見る 詳細を閉じる

    The steady two-dimensional stagnation-point flow of a rarefied gas impinging obliquely on an infinitely wide plane wall is investigated on the basis of kinetic theory. Assuming that the overall flow field has a length scale of variation much longer than the mean free path of the gas molecules and that the Mach number based on the characteristic flow speed is as small as the Knudsen number (the mean free path divided by the overall length scale of variation), one can exploit the result of the asymptotic theory (weakly nonlinear theory) for the Boltzmann equation, developed by Sone, that describes general steady behavior of a slightly rarefied gas over a smooth boundary [Y. Sone, in: D. Dini (ed.) Rarefied Gas Dynamics, Vol. 2, pp. 737-749. Editrice Tecnico Scientifica, Pisa (1971)]. By solving the fluid-dynamic system of equations given by the theory, the precise description of the velocity and temperature fields around the plane wall is obtained.

︎全件表示 ︎最初の5件までを表示

MISC 20

  1. 航空工学における大規模非定常流体解析のデータ可視化 招待有り

    阿部 圭晃

    日本可視化情報学会誌 41 (162) 7-8 2021年10月

  2. 分割型移流項を用いた高次精度流束再構築法の実用計算における安定性について

    渡邉誉良, 阿部圭晃, 芳賀臣紀, 高木亮治, 大山聖, 野々村拓, 宮路幸二

    数値流体力学シンポジウム講演論文集(CD-ROM) 32nd ROMBUNNO.C10‐5 2018年

    ISSN:2433-2674

  3. LW‐ACMにおける物体壁面境界の取り扱い方法に関する比較検討

    大西順也, 阿部圭晃, 野々村拓, 青野光

    日本機械学会計算力学講演会論文集(CD-ROM) 30th ROMBUNNO.319 2017年9月15日

  4. 高速流体力学に関する学術研究

    野々村拓, 青野光, 寺門大毅, 阿部圭晃, SLAIMAN Taufik, 李東輝, 福本浩章, NUCERA Fortunate, 浅野兼人, 森平光一, 松原暁良, 森中一誠, 加藤大祐, 小澤雄太, 原田拓弥, 中野宏章, DANIELE Sirigatti

    宇宙航空研究開発機構特別資料 JAXA-SP-(Web) (16-003) 115‐116 (WEB ONLY) 2016年9月30日

    ISSN:1349-113X

  5. 混合型移流項に基づく超高次精度流束再構築法の安定化とその検証計算

    阿部圭晃, 森中一誠, 芳賀臣紀, 野々村拓, 宮路幸二

    日本機械学会計算力学講演会論文集(CD-ROM) 29th ROMBUNNO.180 2016年9月21日

  6. LW‐ACMのマクロ変数での計算機への実装とそのアルゴリズム理解(第一報)

    大西順也, 阿部圭晃, 野々村拓, 青野光

    日本機械学会計算力学講演会論文集(CD-ROM) 29th ROMBUNNO.312 2016年9月21日

  7. A note on implementation of boundary variation diminishing algorithm to high-order local polynomial-based schemes

    Yoshiaki Abe, Ziyao Sun, Feng Xiao

    2016年5月27日

    詳細を見る 詳細を閉じる

    A novel approach for selecting appropriate reconstructions is implemented to<br /> the hyperbolic conservation laws in the high-order local polynomial-based<br /> framework, e.g., the discontinuous Galerkin (DG) and flux reconstruction (FR)<br /> schemes. The high-order polynomial approximation generally fails to correctly<br /> capture a strong discontinuity inside a cell due to the Runge phenomenon, which<br /> is replaced by more stable approximation on the basis of a troubled-cell<br /> indicator such as that used in the total variation bounded (TVB) limiter. This<br /> paper examines the applicability of a new algorithm, so-called boundary<br /> variation diminishing (BVD) reconstruction, to the weighted essentially<br /> non-oscillatory (WENO) methodology in the FR framework including the nodal type<br /> DG method. The BVD reconstruction adaptively chooses a proper approximation for<br /> the solution function so as to minimize the jump between values at the left-<br /> and right-side of cell boundaries without any ad hoc constant such as the TVB<br /> parameter. Several numerical tests are conducted for a linear advection<br /> equation as well as the selection of an appropriate reconstruction, where the<br /> results of the BVD algorithm are comparable to those using the conventional TVB<br /> limiter. Note that the present work is limited to third or lower order<br /> polynomials, leaving the implementations for higher-order schemes a future<br /> work.

  8. 流束再構築法の保存/非保存型メトリックの保存特性と精度に関する考察

    宮路幸二, 阿部圭晃, 芳賀臣紀, 野々村拓

    数値流体力学シンポジウム講演論文集(CD-ROM) 30th ROMBUNNO.B03‐3 2016年

  9. 高次精度流束再構築法における自乗量保存型スキームの安定性

    森中一誠, 阿部圭晃, 野々村拓, 芳賀臣紀, 宮路幸二

    日本機械学会計算力学講演会論文集(CD-ROM) 28th (28) ROMBUNNO.304-1"-"304-2" 2015年10月9日

    出版者・発行元:一般社団法人日本機械学会

    ISSN:1348-026X

    詳細を見る 詳細を閉じる

    高精度流束再構築法(FR法)の数値安定性を向上させることを目指し、1次元オイラー方程式における自乗量保存型スキームの定式化と数値実験に取り組んだ。計算結果より、移流項に擬混合型を用いることで安定性が向上することを確認した。また、FR法における解定義点や修正関数の選び方が安定性に影響を及ぼすことを確認した。

  10. 移流項に擬混合型を用いた高次精度流束再構築法における保存量保存性

    森中一誠, 阿部圭晃, 芳賀臣紀, 野々村拓, 宮路幸二

    数値流体力学シンポジウム講演論文集(CD-ROM) 29th ROMBUNNO.B06‐2 2015年

  11. 高次精度保存型FR法での一様流保持におけるエイリアシング誤差の除去

    阿部圭晃, 野々村拓, 芳賀臣紀, 藤井孝藏

    日本機械学会計算力学講演会論文集(CD-ROM) 27th ROMBUNNO.2804 2014年11月21日

  12. S0550303 DBDプラズマアクチュエータによる低レイノルズ数2次元翼周り動的剥離制御の数値解析([S055-03]プラズマアクチュエータ(3),流体工学部門)

    加藤 宏基, 阿部 圭晃, 青野 光, 野々村 拓, 藤井 孝藏

    年次大会 : Mechanical Engineering Congress, Japan 2014 "S0550303-1"-"S0550303-5" 2014年9月7日

    出版者・発行元:一般社団法人日本機械学会

    詳細を見る 詳細を閉じる

    This paper investigates effective and robust feedback control of dynamic separation around the NACA0015 airfoil using a dielectric barrier discharge plasma actuator. A chord-based Reynolds number is 23,000, and an angle of attack varies from 7 to 15 degrees. The feedback control is based on the pressure coefficient on the airfoil surface (i.e., 0.4-chord location). Although the aerodynamic performance using the feedback control is comparable with that using the continuous mode, the input energy of the feedback control is significantly (approximately by 50%) reduced from that of the continuous mode.

  13. 2メーター直径3枚ブレード回転機器模型まわり剥離流れへのプラズマ気流制御効果に関する数値解析

    青野光, 阿部圭晃, 岡田浩一, 岡田浩一, 佐藤允, 焼野藍子, 野々村拓, 藤井孝藏

    日本機械学会年次大会講演論文集(CD-ROM) 2014 ROMBUNNO.S0550404 2014年9月6日

  14. 3次元移動変形格子での高次精度保存型FR法における一様流保持

    阿部圭晃, 芳賀臣紀, 野々村拓, 藤井孝藏

    数値流体力学シンポジウム講演論文集(CD-ROM) 28th ROMBUNNO.C06-4 2014年

  15. 回転する計算格子の下で幾何学的保存則を満足する高次精度差分スキームの提案

    阿部圭晃, 野々村拓, 佐藤允, 青野光, 藤井孝藏

    計算工学講演会論文集(CD-ROM) 18 ROMBUNNO.F-10-3 2013年6月19日

    ISSN:1342-145X

  16. シンセティックジェットを用いた翼周り剥離流れの制御における大規模な渦構造の時空間での可視化 (第41回可視化情報シンポジウム講演論文集) -- (オーガナイズドセッション 乱流および乱流遷移現象の可視化Ⅰ)

    阿部 圭晃, 野々村 拓, 藤井 孝藏

    可視化情報学会誌 = ournal of the Visualization Society of Japan 33 (1) 161-166 2013年

    出版者・発行元:可視化情報学会

    ISSN:0916-4731

  17. 高次精度保存型FR法における一様流保持

    阿部圭晃, 芳賀臣紀, 野々村拓, 藤井孝藏

    数値流体力学シンポジウム講演論文集(CD-ROM) 27th ROMBUNNO.C04-2 2013年

  18. 809 移動変形格子を用いた高次精度差分スキームにおける対称保存型メトリックの幾何学的解釈(OS8-2.工学・医療工学における移動境界問題(2),OS・一般セッション講演)

    阿部 圭晃, 飯塚 宣行, 野々村 拓, 藤井 孝藏

    計算力学講演会講演論文集 2012 (25) 16-18 2012年10月6日

    出版者・発行元:一般社団法人日本機械学会

    ISSN:1348-026X

    詳細を見る 詳細を閉じる

    One of the techniques for the discretization of time metrics and the Jacobian is to rewrite their analytical expression into conservative forms. In this research, we give the geometrical interpretation for discretized conservative metrics evaluated by any higher-order finite difference method.

  19. シンセティックジェットによる翼周り剥離流れの制御に関するLES : スパン方向渦の解析

    阿部圭晃

    第26回数値流体力学シンポジウム講演論文集, 2012 2012年

  20. DBDプラズマアクチュエータを用いた翼剥離流れ制御の非定常流れ場解析

    佐藤允, 岡田浩一, 阿部圭晃, 青野光, 野々村拓, 藤井孝藏

    数値流体力学シンポジウム講演論文集(CD-ROM) 26th ROMBUNNO.D10-3 2012年

︎全件表示 ︎最初の5件までを表示

講演・口頭発表等 65

  1. Development of a low-cost computing method for static aeroelasticity and deep dynamical modeling for unsteady FSI

    Tomoki Yamazaki, Yoshiaki Abe, Freddie D Witherden, Tomonaga Okabe

    76th Annual Meeting of the Division of Fluid Dynamics 2023年11月19日

  2. Structural Design of Composite Aircraft Based on Static Aeroelastic Analysis

    RASHMI KANT, Yoshiaki Abe

    76th Annual Meeting of the Division of Fluid Dynamics 2023年11月19日

  3. Structural Sizing of a WingFuselage Model Using Oneway Coupling Analysis

    Rashmikant, T. Yamazaki, Y. Abe

    Twentieth International Conference on Flow Dynamics 2023年11月7日

  4. Simulation Framework for Wake-Induced Aeroelastic Phenomena

    K. Otsuka, T. Yamazaki, Y. Abe, T. Haga

    Twentieth International Conference on Flow Dynamics 2023年11月7日

  5. Fully-partitioned Method for Static Aeroelasticity and Deep Dynamical Modeling for Unsteady Fluid-structure Interaction

    T. Yamazaki, Y. Abe, F. D. Witherden, T. Okabe

    Twentieth International Conference on Flow Dynamics 2023年11月7日

  6. Analysis of oscillation behavior of droplet in aerodynamic levitaion

    Shingo Ishihara, Yoshiaki Abe, Masayoshi Adachi

    2023年9月10日

  7. Digital Aircraft Design with Carbon Fiber Reinforced Thermoplastics

    Yoshiaki Abe

    Computational Multi-Physics, Multi-Scales and Multi Big Data (CM3 Transport 2023) 2023年7月15日

  8. Multi-Modal Fully Partitioned Method for the Static Aeroelastic Analysis of Composite Aircraft Wings

    Tomoki Yamazaki, Yoshiaki Abe, Shugo Date, Tomonaga Okabe, Shigeru Obayashi

    15th Conference on Evolutionary and Deterministic Methods for Design, Optimization and Control 2023年6月2日

  9. 制御あり動的モード分解(DMDc)の省メモリ型モード選択と 流体構造連成解析への導入に関する基礎検討

    味村桂甫, 阿部圭晃, 岡部朋永

    日本航空宇宙学会北部支部2023年講演会 2023年3月22日

  10. Buckling tolerance design of aircraft fuselage using carbon fiber reinforced thermoplastic (CFRTP)

    Haruka Kaneda, Shugo Date, Yoshiaki Abe, Tomonaga Okabe

    AIAA Scitech 2023 2023年1月27日

  11. 流体構造連成解析に基づく複合材航空機の最適設計 招待有り

    阿部 圭晃

    日本機械学会計算力学部門 解析・設計の代替モデリング研究会 第6回研究会 2022年12月22日

  12. 高温高反応性溶融金属の熱物性測定に向けたガス浮遊法の数値解析 招待有り

    阿部 圭晃

    第9回東北大学若手アンサンブルワークショップ 2022年11月22日

  13. 高温高反応性溶融金属の熱物性測定に向けたガス浮遊法の数値解析

    阿部 圭晃, 石原 真吾, 安達 正芳

    日本機械学会 第 100 期流体工学部門講演会 2022年11月13日

  14. Development of a correction method for surface tension measured by aerodynamic levitation

    Shingo Ishihara, Yoshiaki Abe, Masayoshi Adachi, Junya Kano

    2022年9月28日

  15. Effects of surface temperature on stability of aerodynamic levitation technique

    Yoshiaki Abe, Masayoshi Adachi, Shingo Ishihara

    The 13th Asian Thermophysical Properties Conference 2022年9月28日

  16. Digital transformation of aircraft design with carbon fiber reinforced plastics

    Yoshiaki Abe, Shigeru Obayashi

    2nd US-Japan Workshop on Data-Driven Fluid Dynamics 2022年9月7日

  17. Design of wind turbine blades made of carbon fiber composite material and examination of reinforcing fiber types

    Tomoki Yamazaki, Shugo Date, Yoshiaki Abe, Tomonaga Okabe

    WCCM-APCOM 2022 2022年8月2日

  18. Boundary Variation Diminishing scheme using β-variable THINC scheme for compressible multiphase flow

    Hiro Wakimura, Yoshiaki Abe, Takanori Haga, Feng Xiao

    WCCM-APCOM 2022 2022年8月2日

  19. Muti-objective design exploration approach for aircraft wing design with carbon fiber reinforced plastics

    Shugo Date, Yoshiaki Abe, Tomonaga Okabe

    WCCM-APCOM 2022 2022年8月2日

  20. 航空機主翼基本設計の高効率化に向けた低コストフラッタ解析の導入に関する検討

    山﨑 智基, 伊達 周吾, 阿部 圭晃, 岡部 朋永

    第54回流体力学講演会 / 第40回航空宇宙数値シミュレーション技術シンポジウム 2022年6月30日

  21. 炭素繊維複合材を用いた航空機主翼設計のデジタル化 招待有り

    阿部 圭晃

    第7回理論応用力学シンポジウム 2022年3月11日

  22. Optimization of Structural Layout for Composite Aircraft Wings

    Y. Inaba, S. Date, H. M. Alfyandy, Y. Abe, K. Shimoyama, T. Okabe, S. Obayashi

    Eighteenth International Conference on Flow Dynamics 2021年10月28日

  23. Re=25,000でホバリングする2次元平板翼の空力解析

    山崎 智基, 阿部 圭晃, 岡部 朋永, 澤田 惠介

    第53回流体力学講演会/第39回航空宇宙数値シミュレーション技術シンポジウム 2021年6月30日

  24. ガスジェット浮遊法における高温球の浮遊安定性

    阿部 圭晃, 小西 貴之, 安達 正芳, 石原 真吾, 岡部 朋永

    第53回流体力学講演会/第39回航空宇宙数値シミュレーション技術シンポジウム 2021年7月1日

  25. Optimum structure design of aircraft wings using carbon fiber reinforced plastics (CFRPs) 招待有り

    Yoshiaki Abe, Shigeru Obayashi, Shugo Date, Keiichi Shirasu, Hikaru Takami, Tomonaga Okabe

    14th International Conference on Evolutionary and Deterministic Methods for Design, Optimization and Control 2021年6月28日

  26. 静空弾解析を用いたCFRP製航空機主翼の空力構造設計における炭素繊維物性の影響評価

    伊達周吾, 阿部圭晃, 山本剛大, 岡部朋永

    日本航空宇宙学会北部支部2021年講演会 2021年3月19日

  27. Effects of fiber and resin properties on composite wing design using multiscale framework

    Shugo Date, Yoshiaki Abe, Takeki Yamamoto, Tomonaga Okabe

    14th World Congress in Computational Mechanics (WCCM) ECCOMAS Congress 2020 2021年1月15日

  28. BVD原理に基づくβ可変THINC法による 衝撃波捕獲スキーム

    脇村 尋, Deng Xi, 阿部圭晃, 肖鋒

    第34回数値流体力学シンポジウム 2020年12月22日

  29. 低レイノルズ数円柱後流に置かれた二次 元剛体翼の振動特性

    長谷沼毅, 阿部圭晃, 岡部朋永

    第34回数値流体力学シンポジウム 2020年12月21日

  30. Dynamics of Wake-Vortices Deflection Over an Airfoil Using Active Morphing Flaps

    Yoshiaki Abe, Takayuki Konishi, Tomonaga Okabe

    APS DFD 2020年11月22日

  31. Investigations on Aerodynamic Effect of Morphing Flap and Distributed Propulsion System

    Yuki Kamiyama, Daisuke Yariwake, Edyta Dzieminska, Aiko Yakeno, Yoshiaki Abe, Shigeru Obayashi

    Seventeenth International Conference on Flow Dynamics 2020年10月28日

  32. High-fidelity Flow Simulation around a Low-pressure Turbine Blade and Cross-platform Implementation with PyFR

    Yoshiaki Abe, Freddie D. Witherden, Kazuhiko Komatsu, Brian C. Vermeire, Peter E. Vincent, Kozo Fujii

    Seventeenth International Conference on Flow Dynamics 2020年10月28日

  33. Aerodynamic Characteristics of Circular Cylinders with Fineness Ratios Lower than 0.5 Measured by a Magnetic Suspension and Balance System

    Masahide Kuwata, Yoshiaki Abe, Sho Yokota, Taku Nonomura, Hideo Sawada, Aiko Yakeno, Keisuke Asai, Shigeru Obayashi

    Seventeenth International Conference on Flow Dynamics 2020年10月26日

  34. Simulations of Flow over Low-Pressure Turbine Blades with PyFR 招待有り

    Yoshiaki Abe

    PyFR Symposium 2020年6月19日

  35. Drag Coefficients of Circular Cylinders with Low Fineness Ratios less than 0.50 measured by 0.1 and 0.3 m Magnetic Suspension and Balance Systems

    Masahide Kuwata, Sho Yokota, Hideo Sawada, Yoshiaki Abe, Aiko Yakeno, Taku Nonomura, Keisuke Asai, Shigeru Obayashi

    2020 AIAA SciTech 2020年1月8日

  36. Interaction Between Fibers and Viscous Flow Evaluated by Simplified Bead-Chain Model and Generalized SPH

    Yoshiaki Abe, Tomonaga Okabe

    72nd Annual Meeting of the APS Division of Fluid Dynamics 2019年11月23日

  37. Towards Fluid-structure Interaction using Assumed Mode Deformation Approach

    Yoshiaki Abe, Shoji Iori, Tomonaga Okabe

    16th International Conference on Flow Dynamics (ICFD2019) 2019年11月8日

  38. Numerical Simulation of Wake Deflection Control around NACA0012 Airfoil using Active Morphing Flaps

    Takayuki Konishi, Yoshiaki Abe, Tomonaga Okabe

    16th International Conference on Flow Dynamics (ICFD2019) 2019年11月8日

  39. Multiscale Design for Composite Aircraft Wings 招待有り

    Yoshiaki Abe, Tomonaga Okabe

    16th International Conference on Flow Dynamics (ICFD2019) 2019年11月7日

  40. High-performance Implementation of Inlet Turbulence Generation for GPU-based Parallel Computation

    Yoshiaki Abe, Freddie D. Witherden, Giorgio Giangaspero, Brian C. Vermeire, Arvind S. Iyer, Peter E. Vincent

    16th International Conference on Flow Dynamics (ICFD2019) 2019年11月7日

  41. Flow Dynamics of Low Fineness Ratio Circular Cylinders Evaluated by IFS 0.1-m MSBS and Large-Eddy Simulation

    Masahide Kuwata, Aiko Yakeno, Yoshiaki Abe, Shigeru Obayashi

    16th International Conference on Flow Dynamics (ICFD2019) 2019年11月6日

  42. Aerostructural Analysis for Composite Aircraft Wings with Various Fiber Properties

    Shugo Date, Yoshiaki Abe, Takeki Yamamoto, Tomonaga Okabe

    16th International Conference on Flow Dynamics (ICFD2019) 2019年11月6日

  43. モーフィングフラップを⽤いた翼後流渦列の能動制御

    ⼩⻄ 貴之, 阿部 圭晃, 岡部朋永

    第57回飛行機シンポジウム 2019年10月17日

  44. Effects of Fiber Property on Composite Wing Design Evaluated by Multiscale Analysis

    Shugo Date, Yoshiaki Abe, Takeki Yamamoto, Tomonaga Okabe

    16th Japan International SAMPE Symposium & Exhibition 2019年9月3日

  45. The effect of inlet turbulence on unsteady flow simulations over an MTU T161 low-pressure turbine blade

    Yoshiaki Abe, Freddie Witherden, Arvind Iyer, Brian Vermeire, Ralf-Dietmar Baier, Antony Jameson, Peter Vincent

    第32回数値流体力学シンポジウム 2018年12月13日

  46. 翼周り剥離流れ制御におけるDBDプラズマアクチュエータと シンセティックジェットの比較 招待有り

    阿部 圭晃

    日本機械学会流体工学部門A-TS 05-24研究会「プラズマアクチュエータ研究会」 第6回シンポジウム 2018年11月15日

  47. Effects of Uncertainty in Bubble Density on Flow Structures in Shock-bubble Interaction 国際会議

    Jonghoon Jin, Xi Deng, Yoshiaki Abe, Feng Xiao

    9th International Conference on Computational Methods 2018年8月6日

  48. Optimal meshes for high-order implicit large-eddy simulation of turbulent boundary layers using Kriging surrogate models 国際会議

    Y. Abe, P. E. Vincent

    ICOSAHOM2018 2018年7月9日

  49. High-order accurate scale-resolving simulations of low-pressure turbine linear cascades using python at petascale 国際会議

    P. E. Vincent, A. S. Iyer, F. D. Witherden, B. C. Vermeire, Y. Abe, Ralf-Dietmar Baier, A. Jameson

    ICOSAHOM2018 2018年7月9日

  50. Stability of Split-Form Flux- Reconstruction Schemes for Airfoil Flow Simulation with High-Order Mesh 国際会議

    T. Watanabe, Y. Abe, T. Haga, R. Takaki, A. Oyama, T. Nonomura, K. Miyaji

    ICCFD10 2018年7月9日

  51. Identifying optimal meshes for high-order implicit large-eddy simulation of turbulent boundary layers using Kriging surrogate models 国際会議

    Y. Abe, P. E. Vincent

    ECCM-ECFD 2018年6月11日

  52. High-order accurate scale-resolving simulations of low-pressure turbine linear cascades using python at petascale 国際会議 招待有り

    P. E. Vincent, A. S. Iyer, F. D. Witherden, B. C. Vermeire, Y. Abe, Ralf-Dietmar Baier, A. Jameson

    ECCM-ECFD 2018年6月11日

  53. Flow Instability on Airfoil Separation Control at Optimum Actuation Frequency 国際会議

    Y. Abe, T. Nonomura, K. Fujii

    24th International Congress of Theoretical and Applied Mechanics 2016年8月21日

  54. Conservation properties of high-order flux reconstruction scheme in split forms 国際会議

    I. Morinaka, Y. Abe, T. Haga, T. Nonomura, K. Miyaji

    VII European Community on Computational Methods in Applied Sciences and Engineering 2016年6月6日

  55. Flux reconstruction scheme in split forms 国際会議

    Y. Abe, I. Morinaka, T. Haga, T. Nonomura, K. Miyaji

    4th International Workshop on High-order CFD Methods 2016年6月5日

  56. Conservative flux-reconstruction schemes towards high-fidelity flow simulation around complex geometries 国際会議 招待有り

    Y. Abe, I. Morinaka, T. Haga, T. Nonomura, K. Miyaji

    Next Generation Transport Aircraft Workshop 2016 2016年3月6日

  57. Fully conservative high-order FR scheme on moving and deforming grids 国際会議

    Y. Abe, T. Haga, T. Nonomura, K. Fujii

    AIAA Aviation 2015年6月22日

  58. Efficient evaluations of symmetric conservative metrics for high-order finite-difference schemes on a rotating grid 国際会議

    Y. Abe, H. Aono, T. Nonomura, K. Fujii

    2nd Frontiers in Computational Physics Conference 2015年6月3日

  59. A dealiasing process for freestream preservation in a high-order conservative FR scheme 国際会議

    Y. Abe, T. Nonomura, T. Haga, K. Fujii

    8th International Conference on Computational Fluids Dynamics 2014年8月6日

  60. Freestream preservation on a high-order conservative FR scheme 国際会議

    Y. Abe, T. Haga, T. Nonomura, K. Fujii

    6th European Conference on Computational Fluid Dynamics 2014年7月20日

  61. Spatial growth of the spanwise disturbance induced by a synthetic jet on separation control over an airfoil 国際会議

    Y. Abe, T. Nonomura, K. Fujii

    AIAA Aerospace Science Meeting 2014年6月16日

  62. Significance of Three-dimensional Unsteady Flows inside the Cavity on Separated-flow Control around an NACA0015 using a Synthetic Jet 国際会議

    Y. Abe, K. Okada, M. Sato, T. Nonomura, K. Fujii

    AIAA Fluid Dynamics Conference and Exhibit 2013年1月4日

  63. On the Discretization of Spatial Metrics Satisfying the GCL identities 国際会議

    Y. Abe, T. Nonomura, N. Iizuka, K. Fujii

    On the Discretization of Spatial Metrics Satisfying the GCL identities 2012年9月10日

  64. Geometries of Discretized Symmetric-conservative Metric Evaluations for Higher-order Finite-Difference Scheme 国際会議

    Y. Abe, N.Iizuka, T. Nonomura, K. Fujii

    23rd International Congress of Theoretical and Applied Mechanics 2012年8月19日

  65. Symmetric-conservative metric evaluations for higher-order finite difference scheme with the GCL identities on three-dimensional moving and deforming mesh 国際会議

    Y. Abe, N. Iizuka, T. Nonomura, K. Fujii

    7th International Conference on Computational Fluid Dynamics 2012年7月5日

︎全件表示 ︎最初の5件までを表示

産業財産権 1

  1. 浮遊液滴の表面張力推定方法

    石原真吾, 阿部圭晃, 安達正芳, 加納純也

    産業財産権の種類: 特許権

共同研究・競争的資金等の研究課題 10

  1. 異なる物理を繋ぐデータ駆動型の連成数理モデルの創出

    阿部 圭晃

    2022年 ~ 2028年

    詳細を見る 詳細を閉じる

    人間が活用出来る自然現象の多くは2つ以上の物理系が組み合わさった「連成現象」です。流体力学など単一の物理系に関する高度な数値解析技術が確立されつつある一方、それらを複雑な連成現象に適用することは未だ容易ではありません。本研究ではデータ駆動型手法を活用した連成数理モデルを創出し、高度な数値解析と実験計測の融合による航空機機体設計への適用を端緒に、複雑連成現象の新たな学理と工学応用への路を拓きます。

  2. 計算計測融合アプローチに基づく高温高反応性溶融体の熱物性測定の新展開

    阿部 圭晃, 石原 真吾, 安達 正芳

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory)

    研究種目:Grant-in-Aid for Challenging Research (Exploratory)

    研究機関:Tohoku University

    2022年6月 ~ 2024年3月

  3. 量子アニーリングが拓く高性能マテリアルインフォマティクス基盤の新展開

    小林 広明, 撫佐 昭裕, 阿部 圭晃, 岡部 朋永, 佐藤 雅之, 小松 一彦, 大関 真之, 菊川 豪太, 觀山 正道

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (A)

    研究機関:Tohoku University

    2019年4月1日 ~ 2023年3月31日

    詳細を見る 詳細を閉じる

    架橋高分子材料における架橋ネットワーク構造形成のシミュレーションの高速化では,分子動力学シミュレーションと連携する形で粗視化粒子スケールのシミュレーションであるDPD(散逸粒子動力学)法を実装した.また,全原子スケールと同様の反応モデルを組み込み,粗視化レベルでの硬化計算を実現した.さらに,DPDシミュレーションによって得られた構造に対し,全原子スケールの構造テンプレートを貼り付けるリバースマッピング手法を開発した.その結果,全原子シミュレーションに対してコンシステントな構造・物性予測と硬化計算の大幅な速度向上を実現した. 高次精度非構造ソルバーを用いた非定常圧縮性流体マクロ解析の大規模実行については,オープンソース(PyFR)のSX-Aurora TSUBASAにおける実装と高速化について研究開発を進めた.その結果,これまで部分的にのみベクトル化が行われていた流束計算のためカーネル(tflux/intcflux)対して,配列の初期化やループ構造の見直しにより完全なベクトル化を達成することが出来た. 分子動力学シミュレーション(Peachgk_md)の高速化については,ベクトル化阻害要因であったリストベクトルにおいて,止まり木法を用いることによってベクトル化が可能であることを明らかにし,Peachgk_mdに止まり木法を実装することによってベクトル化率を98.8%まで向上させ,その結果,演算性能が6.5倍に向上した. アニーリングマシンと高性能計算システムの連携によるクラスタリング手法の開発では、クラスタリング条件を定義する制約項をQUBOとは別に定義するアニーリングベースのクラスタリングを量子アニーリングマシンやデジタルアニーリングマシンで行い、QUBO生成などの前処理および、データ集計の後処理などに従来の高性能計算システムを活用する手法を開発した。

  4. アーキテクチャに依存しない超高次精度かつ低散逸の複雑形状周り非定常乱流数値解析

    阿部 圭晃

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Early-Career Scientists

    研究種目:Grant-in-Aid for Early-Career Scientists

    研究機関:Tohoku University

    2019年4月 ~ 2021年3月

    詳細を見る 詳細を閉じる

    今年度は,非構造高次精度法の一種である流束再構築法(Flux Reconstruction 法:FR 法)に基づく圧縮性流体ソルバーを用いたGNLG(Gulfstream G550 Nose Landing Gear:航空機着陸脚)周りの非定常乱流解析において,従来の安定化法(overintegrationによるdealias処理)が空間5次精度の離散化において十分に有効でなく,既存の安定化法だけではGNLGクラスの複雑形状周りの流れ場を安定に解き進めることは難しいと分かった.また同時に,曲がった形状を精度良く再現する空間メッシュの問題もあり, 特に四面体高次要素と六面体高次要素を繋ぐピラミッド型の要素において底面が曲線で構成されたセルにおける一様流保持の問題があることが判明した.これらは一般的な非構造高次精度法において未だ未解決の課題であり,次年度取り組むことを計画している. さらに,当初の計画を前倒しして現在のFR法ソルバーを新しい計算アーキテクチャの一種であるベクトルマシン(NEC SX-Aurora)に適合するよう改変を試みた. SX-Aurora上での実行が可能であることと,同アーキテクチャの特徴である高いメモリバンド幅を生かした解析が可能であることを実証し,FR法に基づく圧縮性流体解析をベクトルマシンで実行した世界初の結果を得た.現在,さらに大規模な並列化計算を目指しプログラムの拡張を進めており,また他の計算機(GPU,CPU)との比較を同じ流体ソルバーを用いて行う基盤を構築することが出来た.

  5. 不確実性を考慮した翼周り剥離流れの制御性能予測モデルの構築

    阿部 圭晃

    2016年4月22日 ~ 2019年3月31日

    詳細を見る 詳細を閉じる

    本課題では,複雑形状周りの圧縮性流れの高精度数値解析手法として高次精度流束再構築法(Flux reconstruction method:FR法)を採用する.不確実性を含む支配方程式の場合,変数の多次元化と解の不連続性から数値不安定性が強まる事が予測され,これらを根本的に解決する手法が必須である. 本年度は,差分法にて有効性が示されてきた「混合型移流項を用いた非線形安定化手法」のFR法への適用を試みた.混合型移流項の適用に際して必要となる定式化と簡単なベンチマークテストは既に終えていた為,本年度は3次元Taylor-Green渦など,より実用的な非線形性の強い乱流場を対象とした数値テストと安定性解析を試みた.その結果,空間16次精度という超高次精度の空間離散化手法を実現する事に成功した.本手法の鍵は,Navier-Stokes方程式の移流項を混合型へ書き換える事で,速度自乗量の保存を実現する事にある.その為に,FR法においては解の定義点をGauss-Lobatto点に置く事,セル界面にて適用される修正関数をg2関数とする事が十分条件である事を見い出した.本結果は2016年8月に行われた高次精度スキームに関する国際ワークショップにおいて発表し,他の参加者の示す高次精度スキーム(空間6次精度程度)よりも数十倍の効率(同一精度の数値解を得る為に必要な計算時間での比較)向上を示す事が出来た.本内容は現在,国際学術誌にて査読中である.また上記のFR法を用いた流体の不確実性評価法構築の第一歩として,Burgers方程式の不確実性評価手法の構築を行った.導出したstochastic Burgers方程式の空間離散化をFR法に基づき行い,簡単な1次元問題に対して安定に計算が行える事を確認した.これらの知見を圧縮性流体解析におけるFR法を用いた不確実性評価へと適用する事が可能と考えている.

  6. Short Projects in Platform for Research in Simulation Methods (PRISM) 競争的資金

    阿部 圭晃

    提供機関:EPSRC

    制度名:Short Projects in Platform for Research in Simulation Methods (PRISM)

    2018年5月 ~ 2018年11月

  7. エクサスケールコンピュータへむけた高速高次精度・非構造流体解析ソルバーの技術確立

    野々村 拓, 芳賀 臣紀, 阿部 圭晃

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Challenging Exploratory Research

    2015年4月1日 ~ 2017年3月31日

    詳細を見る 詳細を閉じる

    本研究では,高速高次精度・非構造流体ソルバーのための技術確立に向けた研究を行った.圧縮性流体解析向けの流束再構築法を対象とし,以下の3つの技術確立を行った.1)移動変形格子上での保存則および一様流保持を満たす適切な保存メトリクスの評価方法を提案し実証した.2)運動エネルギの保存を近似的に満たす分割型の定式化を証明し,16次精度の超高次精度解析で計算が安定化することを実証した.3)キャッシュ・レジスタチューニングを行い,メモリアクセスを高速化することで,チューニング前から比較して2倍の速度を実現した.これらにより,高速高効率に解析できる非構造格子高次精度解析手法の基礎技術が開発できた

  8. 日本学術振興会・特別研究員PD 競争的資金

    阿部 圭晃

    2016年4月 ~ 2016年10月

  9. シンセティックジェットによる翼周りの剥離流れ制御に関する数値的研究

    阿部 圭晃

    2013年4月1日 ~ 2016年3月31日

    詳細を見る 詳細を閉じる

    前年度までに解析を行ったシンセティックジェット(SJ)による翼周り剥離流れ制御に対し,同様のマイクロデバイスであり近年注目を集めているプラズマアクチュエータ(PA)による剥離制御に関する高精度シミュレーションを行い,制御メカニズムと最適な駆動パラメータの比較を行った.まず,最適な駆動周波数F+(一様流速度と翼弦長で無次元化した周波数)は両デバイス共に6から20程度に局在する事が明らかとなった.しかし,投入運動量の大きい時にはPAが高い揚抗比を示す一方,投入運動量の小さい時にはSJが高い揚抗比を示した.これはデバイスにより誘起される擾乱に違いを生じる為と考えられ,その要因を以下のように切り分けた:A)主流に沿う方向に直接運動量を付加する効果はPAの方が強い;B)翼スパン方向の変動成分(流れの3次元性)はSJの方が強い;C)SJによる誘起流れは局所性の強い流速分布を有する;D)バースト駆動を行うPAは交流電圧を使用する事に伴いSt=100以上の高周波成分が強く投入される.以上の特性のうち,投入運動量の大きい場合にはAの効果が強く現れPAの剥離制御性能が高くなり,小さい場合にはBに基づきSJの剥離制御性能が向上すると考えられる.このようにデバイス特性の違いに起因して制御性能がわずかに異なる事を示したが,一方で剥離制御に重要な主流方向運動量の交換の観点では,両デバイス共に乱流混合による交換作用と大規模秩序渦による乱流渦の連行作用の双方が鍵となる事を明らかにした.また誘起擾乱に対する線形安定性解析を施し両デバイス共に前縁付近で擾乱の線形成長領域が現れる事を示し,同様のメカニズムで最適な駆動周波数が局在する事を明らかにした.このように,個々のデバイス間の誘起擾乱の違いによる制御性能のわずかな差異を除き,最適な剥離流れ制御を行うメカニズムには普遍性の高い要素が存在する可能性を示した.

  10. 日本学術振興会・特別研究員DC1 競争的資金

    阿部 圭晃

    2013年4月 ~ 2016年3月

︎全件表示 ︎最初の5件までを表示

担当経験のある科目(授業) 1

  1. 航空システム特論I 東北大学

その他 2

  1. Innovation Award in the Technology and Products category in REIFEN 2014

    詳細を見る 詳細を閉じる

    企業との共同研究による受賞 “Yokohama Rubber and JAXA Joint R&D Effort Succeeds in World’s First Simulation of Acoustics around a Rolling Tire,” ( http://www.yrc.co.jp/release/?id=2256&lang=ja )

  2. ニュースリリース:「世界初, 横浜ゴムと宇宙科学研究所の共同研究チームが走行するタ イヤ周りの流体音響 シミュレーションに成功」

    詳細を見る 詳細を閉じる

    企業との共同研究におけるニュースリリース http://www.yrc.co.jp/release/?id=2225&lang=ja