Details of the Researcher

PHOTO

Hiroyuki Asada
Section
Graduate School of Engineering
Job title
Assistant Professor
Degree

  • 博士（工学）（東北大学）

  • 修士（工学）（東北大学）

Research History 4

  • 2023/04 - Present
    Tohoku University　Faculty of Engineering Department of Mechanical and Aerospace Engineering　assistant professor

  • 2021/03 - 2023/03
    Tohoku University　Faculty of Engineering Department of Mechanical and Aerospace Engineering　project assistant professor (research)

  • 2020/04 - 2021/02
    Tohoku University　Faculty of Engineering Department of Mechanical and Aerospace Engineering　academic researcher

  • 2018/04 - 2020/03
    Ritsumeikan University　College of Science and Engineering　assistant professor

Education 2

  • Tohoku University　School of Engineering　Aerospace Engineering

    2015/04 - 2018/03

  • Tohoku University　School of Engineering　Aerospace Engineering

    2013/04 - 2015/03

Committee Memberships 2

  • 日本機械学会　流体工学部門講習会WG

    2023/02 - 2025/03

  • 日本流体力学会　日本流体力学会 年会2024 実行委員

    2023/11 - 2024/09

Professional Memberships 2

  • 日本流体力学会

  • The Japan Society for Aeronautical and Space Sciences

Research Interests 1

  • computational flud dynamics (CFD), high-fidelity simulation, data science, turbulent flow, aerospace engineering

Research Areas 2

  • Aerospace, marine, and maritime Engineering / Aerospace engineering /

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Fluid engineering /

Awards 6

  1. 次世代研究者賞

    2022/03　シンポジウム「富岳百景」実行委員会　高忠実LESを実現する圧縮性流体解析手法 ~航空機離着陸形態まわりLES~

  2. ベストCFDグラフィックス・アワード

    2021/12　日本流体力学会　航空機フライト試験の代替に向けて〜高忠実LESによる航空機全機解析〜

  3. President's award

    2018/03　Tohoku University

  4. Best Student Award

    2016/05　Next Generation Transport Aircraft Workshop

  5. Best presentation award at 47th Fluid Dynamics Conference

    2015/07　JSASS

  6. 日本機械学会畠山賞

    2013/03　社団法人日本機械学会

Show all ︎Show 5

Papers 25

  1. Exact parallelized dynamic mode decomposition with Hankel matrix for large-scale flow data Peer-reviewed

    Hiroyuki Asada, Soshi Kawai

    Theoretical and Computational Fluid Dynamics　39　(1)　2024/12/07

    Publisher: Springer Science and Business Media LLC

    DOI： 10.1007/s00162-024-00730-0 　

    ISSN： 0935-4964

    eISSN： 1432-2250

    More details Close

    Abstract An exact parallel algorithm of dynamic mode decomposition (DMD) with Hankel matrices for large-scale flow data is proposed. The proposed algorithm enables the DMD and the Hankel DMD for large-scale data obtained by high-fidelity flow simulations, such as large-eddy simulations or direct numerical simulations using more than a billion grid points, on parallel computations without any approximations. The proposed algorithm completes the computations of the DMD by utilizing block matrices of $$X^TX\in \mathbb {R}^{k\times k}$$ (where $$X\in \mathbb {R}^{n\times k}$$ is a large data matrix obtained by high-fidelity simulations, the number of snapshot data is $$n > rsim 10^9$$, and the number of snapshots is $$k\lesssim O(10^3)$$) without any approximations: for example, the singular value decomposition of X is replaced by the eigenvalue decomposition of $$X^TX$$. Then, the computation of $$X^TX$$ is parallelized by utilizing the domain decomposition often used in flow simulations, which reduces the memory consumption for each parallel process and wall-clock time in the DMD by a factor approximately equal to the number of parallel processes. The parallel computation with communication is performed only for $$X^TX$$, allowing for high parallel efficiency under massively parallel computations. Furthermore, the proposed exact parallel algorithm is extended to the Hankel DMD without any additional parallel computations, realizing the Hankel DMD of large-scale data collected by over a billion grid points with comparable cost and memory to the DMD without Hankel matrices. Moreover, this study shows that the Hankel DMD, which has been employed to enrich information and augment rank, is advantageous for large-scale high-dimensional data collected by high-fidelity simulations in data reconstruction and predictions of future states (while prior studies have reported such advantages for low-dimensional data). Several numerical experiments using large-scale data, including laminar and turbulent flows around a cylinder and transonic buffeting flow around a full aircraft configuration, demonstrate that (i) the proposed exact parallel algorithm reproduces the existing non-parallelized Hankel DMD, (ii) the Hankel DMD for large-scale data consisting of over a billion grid points is feasible by using the proposed exact parallel algorithm with high parallel efficiency on more than 6 thousand CPU cores, and (iii) the Hankel DMD has advantages for high-dimensional data such as $$n > rsim 10^9$$. Graphical abstract

  2. Kinetic Energy and Entropy Preserving (KEEP) Flux Reconstruction Schemes Based on Gauss-Legendre Nodes

    Issei Homma, Hiroyuki Asada, Soshi Kawai

    AIAA AVIATION FORUM AND ASCEND 2024　2024/07/27

    Publisher: American Institute of Aeronautics and Astronautics

    DOI： 10.2514/6.2024-3789 　

  3. Aeroacoustics Simulations Using Kinetic-Energy and Entropy Preserving (KEEP) Schemes

    Hiroyuki Asada, Seiya Sato, Naoki Miwa, Soshi Kawai

    30th AIAA/CEAS Aeroacoustics Conference (2024)　2024/05/30

    Publisher: American Institute of Aeronautics and Astronautics

    DOI： 10.2514/6.2024-3244 　

  4. Temporal discretization for improving kinetic-energy and entropy preservation properties in KEEP schemes Peer-reviewed

    Hiroyuki Asada, Kanako Maruyama, Soshi Kawai

    Computers & Fluids　270　106143-106143　2024/02

    Publisher: Elsevier BV

    DOI： 10.1016/j.compfluid.2023.106143 　

    ISSN： 0045-7930

  5. Transonic buffet simulations over NASA-CRM by wall-modeled large-eddy simulation using Cartesian-grid-based flow solver FFVHC-ACE

    Hirotaka Maeyama, Hiroyuki Asada, Soshi Kawai

    AIAA SCITECH 2024 Forum　2024/01/04

    Publisher: American Institute of Aeronautics and Astronautics

    DOI： 10.2514/6.2024-2548 　

  6. POD and DMD of three-dimensional transonic aircraft buffet using large-scale LES data

    Hiroyuki Asada, Soshi Kawai

    AIAA SCITECH 2024 Forum　2024/01/04

    Publisher: American Institute of Aeronautics and Astronautics

    DOI： 10.2514/6.2024-0494 　

  7. FFVHC-ACE: Fully Automated Cartesian-Grid-Based Solver for Compressible Large-Eddy Simulation Peer-reviewed

    Hiroyuki Asada, Yoshiharu Tamaki, Ryoji Takaki, Takaaki Yumitori, Shun Tamura, Keita Hatanaka, Kazuhiro Imai, Hirotaka Maeyama, Soshi Kawai

    AIAA Journal　61　(8)　1-19　2023/04/02

    Publisher: American Institute of Aeronautics and Astronautics (AIAA)

    DOI： 10.2514/1.j062593 　

    ISSN： 0001-1452

    eISSN： 1533-385X

    More details Close

    This study presents a fully automated Cartesian-grid-based compressible flow solver, named FrontFlow/Violet Hierarchical Cartesian for Aeronautics based on Compressible-flow Equations (FFVHC-ACE), for large-eddy simulation (LES) and its aeronautical applications. FFVHC-ACE enables high-fidelity LES of high-Reynolds-number flows around complex geometries by adopting three key numerical methods: hierarchical Cartesian grids, wall modeling in LES, and the kinetic-energy and entropy preserving (KEEP) scheme. The hierarchical Cartesian grids allow fully automated grid generation for complex geometries in FFVHC-ACE, and high-fidelity LES of high-Reynolds-number flows around complex geometries is realized by the wall modeling and the KEEP scheme on the non-body-fitted hierarchical Cartesian grids. We apply FFVHC-ACE to wall-modeled LES around high-lift aircraft configurations at wind-tunnel-scale Reynolds number [Formula: see text] and real-flight Reynolds number [Formula: see text], demonstrating the capability of FFVHC-ACE for fully automated grid generation and high-fidelity simulations around complex aircraft configurations. The computed flowfield and aerodynamic forces at the wind-tunnel-scale Reynolds number agree well with the experimental data provided in the past AIAA High Lift Prediction Workshop (Rumsey et al., Journal of Aircraft, Vol. 56, No. 2, 2019, pp. 621–644). Furthermore, the wall-modeled LES at the real-flight Reynolds number shows good agreement of the lift coefficient with flight-test data.

  8. Identifying the Self-Sustaining Mechanisms of Transonic Airfoil Buffet with Resolvent Analysis Peer-reviewed

    Yuta Iwatani, Hiroyuki Asada, Chi-An Yeh, Kunihiko Taira, Soshi Kawai

    AIAA Journal　61　(6)　1-12　2023/03/31

    Publisher: American Institute of Aeronautics and Astronautics (AIAA)

    DOI： 10.2514/1.j062294 　

    ISSN： 0001-1452

    eISSN： 1533-385X

    More details Close

    The self-sustaining mechanisms of shock oscillations in transonic airfoil buffet are studied by wall-resolved large-eddy simulation (LES) and resolvent analysis. The LES successfully reproduces the large-scale shock oscillations over a transonic OAT15A airfoil, and the resolvent analysis using the high-fidelity LES data reveals the input–output relations in the self-sustained shock oscillations. Based on the input–output relations revealed by the resolvent analysis, this study identifies two mechanisms of the self-sustained shock oscillations. The first mechanism is closely tied to the periodic variations of the shock-induced separation height, whereas the second mechanism is related to the pressure dynamics around the shock wave. The mechanisms of the self-sustained shock oscillations identified by the input–output relations are examined in detail along with the high-fidelity LES data to aid the understanding of the feedback formulations in transonic airfoil buffet.

  9. Conservative low-pass filter with compact stencils for hierarchical Cartesian mesh Peer-reviewed

    Hiroyuki Asada, Soshi Kawai

    Computers & Fluids　252　105769-105769　2023/02

    Publisher: Elsevier BV

    DOI： 10.1016/j.compfluid.2022.105769 　

    ISSN： 0045-7930

  10. Compressible flow solver FFVHC-ACE for fully automated LES of aeronautical flows

    Hiroyuki Asada, Yoshiharu Tamaki, Ryoji Takaki, Soshi Kawai

    AIAA SCITECH 2023 Forum　2023/01/19

    Publisher: American Institute of Aeronautics and Astronautics

    DOI： 10.2514/6.2023-1227 　

  11. Fully-automated high-fidelity LES around high-lift aircraft configuration near stall

    Hiroyuki Asada, Soshi Kawai

    Eleventh International Conference on Computational Fluid Dynamics (ICCFD11)　2022/07

  12. Wall-modeled LES around the CRM-HL using Fully-automated Cartesian-grid-based Flow Solver FFVHC-ACE

    Yoshiharu Tamaki, Hiroyuki Asada, Ryoji Takaki, Soshi Kawai

    AIAA AVIATION 2022 Forum　2022/06/27

    Publisher: American Institute of Aeronautics and Astronautics

    DOI： 10.2514/6.2022-3435 　

  13. POD, DMD, and resolvent analysis of transonic airfoil buffet

    Yuta Iwatani, Hiroyuki Asada, Soshi Kawai

    AIAA SCITECH 2022 Forum, AIAA Paper 2022-0461　2022/01/03

    Publisher: American Institute of Aeronautics and Astronautics

    DOI： 10.2514/6.2022-0461 　

  14. LES of full aircraft configuration using non-dissipative KEEP scheme with conservative explicit filter

    Hiroyuki Asada, Soshi Kawai

    AIAA SciTech Forum 2022, AIAA Paper 2022-0449　2022/01

    Publisher: American Institute of Aeronautics and Astronautics

    DOI： 10.2514/6.2022-0449 　

  15. Dispersion and dissipation analysis for unphysical modes of high-order discontinuous galerkin methods

    Hiroyuki Asada

    AIAA Scitech 2020 Forum　1 PartF　1-9　2020

    DOI： 10.2514/6.2020-1317 　

  16. A Simple Cellwise High-order Implicit Discontinuous Galerkin Scheme for Unsteady Turbulent Flows Peer-reviewed

    Hiroyuki ASADA, Soshi KAWAI

    TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES　62　(2)　93-107　2019

    Publisher: Japan Society for Aeronautical and Space Sciences

    DOI： 10.2322/tjsass.62.93 　

    ISSN： 0549-3811

    eISSN： 2189-4205

    More details Close

    A simple cellwise implicit time integration scheme for high-order discontinuous Galerkin (DG) methods is presented for solving unsteady turbulent flows. One motivation of this study is to utilize the advantages of the cellwise feature of DG methods in implicit time integration to accurately predict the time evolution of unsteady turbulent flows. Our approach is to extend a block Jacobi (BJ) scheme to high-order implicit DG schemes. With the BJ scheme, the cellwise feature is ensured because sweeps referring to up-to-date solutions in nearby cells are not required, and accurate time evolution can be simulated by iteratively solving a linear system formulated in implicit time integration. Although the computational cost required for iterative solutions is of some concern, we found that few sub-iterations are needed to simulate unsteady turbulent flows accurately when the flowfield is well-resolved by high-order DG methods. These advantages are demonstrated through problems such as canonical vortex advection and the inviscid Taylor–Green vortex. The developed BJ-based implicit DG methods were applied to a large eddy simulation of turbulent channel flow, and the results show that, in addition to being a cellwise scheme, the proposed scheme outperforms explicit time integration in terms of the computation time.

  17. A sponge layer for accurate aeroacoustic simulations using high-order discontinuous galerkin methods

    Hiroyuki Asada, Yoshifumi Ogami

    AIAA Scitech 2019 Forum　2019

    DOI： 10.2514/6.2019-1805 　

  18. Basic Investigation of Aeroacoustics Simulations using LES and High-Order DG methods

    Hiroyuki Asada, Yoshifumi Ogami

    29th International Symposium on Transport Phenomena (ISTP29)　2018/09

  19. A quadrature simplification method for fast implicit discontinuous Galerkin schemes Peer-reviewed

    Hiroyuki Asada, Soshi Kawai, Keisuke Sawada

    Computers and Fluids　167　249-264　2018/05/15

    Publisher: Elsevier Ltd

    DOI： 10.1016/j.compfluid.2018.03.035 　

    ISSN： 0045-7930

  20. Aerodynamic Prediction of NASA Common Research Model Using High-order DG Methods Peer-reviewed

    Hiroyuki ASADA, Soshi KAWAI, Keisuke SAWADA

    AEROSPACE TECHNOLOGY JAPAN, THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES　17　179-188　2018

    Publisher: Japan Society for Aeronautical and Space Sciences

    DOI： 10.2322/astj.jsass-d-17-00033 　

    eISSN： 1884-0477

    More details Close

    Aerodynamics coefficients of NASA common research model (NASA-CRM) are computationally investigated by revisiting some test cases appeared in aerodynamics prediction challenge (APC) using high-order discontinuous Galerkin (DG) methods. While the employed high-order DG methods reasonably well predict the overall aerodynamics for the NASA-CRM, some discrepancies appear between the CFD and experimental data, especially in a lift and a pitching moment at low angle of attack. Although those discrepancies still exist, installing a sting enhances the reproduction of experimental data of pitching moment. Additionally, fluid-structure coupled simulations used to consider aero-elastic deformations give better agreements of the pitching moment with experimental data.

  21. High-order implicit discontinuous galerkin scheme for unsteady turbulent flows

    Hiroyuki Asada, Soshi Kawai

    AIAA SciTech Forum - 55th AIAA Aerospace Sciences Meeting　62　(2)　93-107　2017

    DOI： 10.2514/6.2017-0739 　

    ISSN： 0549-3811

  22. High-order cellwise relaxation implicit discontinuous galerkin scheme for unsteady flow computations

    Hiroyuki Asada, Soshi Kawai, Keisuke Sawada

    54th AIAA Aerospace Sciences Meeting　0　2016

    DOI： 10.2514/6.2016-1335 　

  23. A fourth order accurate cellwise relaxation implicit disconstinuous galerkin scheme for solving RANS equations

    Hiroyuki Asada, Kanako Yasue, Yousuke Ogino, Keisuke Sawada

    53rd AIAA Aerospace Sciences Meeting　2015

    Publisher: American Institute of Aeronautics and Astronautics Inc, AIAA

    DOI： 10.2514/6.2015-0057 　

  24. Improvement of Cellwise Relaxation Implicit Discontinuous Galerkin Scheme

    Hiroyuki Asada, Kanako Yasue, Yosuke Ogino, Keisuke Sawada

    COMPSAFE2014　2014/03

  25. A third order accurate cellwise relaxation implicit Discontinuous Galerkin scheme for unstructured hybrid meshes Peer-reviewed

    Hiroyuki Asada, Yousuke Ogino, Kanako Yasue, Keisuke Sawada

    Mathematical Problems in Engineering　2014　(176752)　1-20　2014

    DOI： 10.1155/2014/176752 　

    ISSN： 1024-123X

    eISSN： 1563-5147

Show all ︎Show first 5

Misc. 1

  1. 「富岳」成果創出加速プログラム 航空機フライト試験を代替する近未来型設計技術の先導的実証研究

    稲富裕光, 淺田啓幸, 粟飯原あや, 今井和宏, 久谷雄一, 河合宗司, 筧雅行, 小泉拓, 松村洋祐, 前山大貴, 三吉郁夫, 高木亮治, 玉置義治

    宇宙航空研究開発機構特別資料 JAXA-SP-(Web)　(23-002)　2023

    ISSN： 2433-2232

Presentations 48

  1. 数百億規模データのハンケルDMDを実現する並列化アルゴリズム

    淺田啓幸, 河合宗司

    日本流体力学会年会2024　2024/09/25

  2. FFVHC-ACEを用いた壁面モデルLESによる高揚力装置/着陸脚まわりの空力音響解析

    淺田啓幸, 河合宗司

    第56回流体力学講演会／第42回航空宇宙数値シミュレーション技術シンポジウム　2024/07/03

  3. Aeroacoustics Simulations Using Kinetic-Energy and Entropy Preserving (KEEP) Schemes

    Hiroyuki Asada, Seiya Sato, Naoki Miwa, Soshi Kawai

    30th AIAA/CEAS Aeroacoustics Conference (2024)　2024/06/06

  4. POD and DMD of three-dimensional transonic aircraft buffet using large-scale LES data

    Hiroyuki Asada, Soshi Kawai

    2024 AIAA SciTech Forum and Exposition　2024/01/08

  5. 非構造格子におけるローパスフィルターの理論解析とKEEPスキームへの適用

    淺田啓幸, 丸山佳那子, 河合宗司

    第37回数値流体力学シンポジウム　2023/12/17

  6. DNS of laminar-to-turbulent transition over a cooled/heated supercritical wing

    Hiroyuki Asada, Yuta Iwatani, Soshi Kawai

    APS 76th Annual Meeting of the Division of Fluid Dynamics (APS-DFD 2023)　2023/11/21

  7. 3次元遷音速バフェット現象の大規模 LESデータに対するPOD/DMD解析

    淺田啓幸, 河合宗司

    第55回流体力学講演会／第41回航空宇宙数値シミュレーション技術シンポジウム　2023/07/13

  8. Compressible flow solver FFVHC-ACE for fully automated LES of aeronautical flows

    Hiroyuki Asada, Yoshiharu Tamaki, Ryoji Takaki, Soshi Kawai

    AIAA Scitech Forum 2023　2023/01/25

  9. 冷却/加熱を伴う超臨界翼型まわり乱流遷移のDNS

    淺田啓幸, 河合宗司

    第36回数値流体力学シンポジウム　2022/12/15

  10. Leading research on innovative aircraft design technologies to replace flight test

    2022/10/28

  11. 翼面冷却・加熱を用いた乱流遷移制御と抵抗低減に関するDNS

    淺田啓幸, 岩谷優汰, 河合宗司

    第60回飛行機シンポジウム　2022/10/12

  12. 航空宇宙分野のHPC/CFD標準ソフトウェアを目指すFFVHC-ACE Invited

    計算工学セミナ(東京理科大学での招待講演)　2022/09

  13. High-Fidelity Wall-Modeled LES around Full Aircraft Configuration near Stall Condition

    15th World Congress on Computational Mechanics & 8th Asian Pacific Congress on Computational Mechanics (WCCM-APCOM 2022)　2022/08

  14. Fully-Automated high-fidelity LES around high-lift aircraft configuration near stall

    Eleventh International Conference on Computational Fluid Dynamics (ICCFD11)　2022/07

  15. 航空機全機高揚力形態・高レイノルズ数条件の高忠実LES

    2022/07

  16. 高忠実LESを実現する圧縮性流体解析手法 ~航空機離着陸形態まわりLES~

    淺田啓幸, 玉置義治, 久谷雄一, 高木亮治, 河合宗司

    スーパーコンピュータ「富岳」成果創出加速プログラムシンポジウム富岳百景（研究交流会）　2022/03/14

  17. LES of full aircraft configuration using non-dissipative KEEP scheme with conservative explicit filter

    Hiroyuki Asada, Soshi Kawai

    AIAA SciTech Forum 2022　2022/01/03

  18. Wall-modeled LES of full aircraft configuration using hierarchical Cartesian mesh and non-dissipative KEEP scheme

    Hiroyuki Asada, Soshi Kawai

    2021/12/14

  19. 実機フライト試験を代替する近未来型設計技術の先導的実証研究

    2021/10

  20. 保存則を満たす階層型直交格子filterの提案とLESへの適用

    淺田啓幸, 河合宗司

    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シンポジウム　2021/07

  21. 階層型直交格子KEEPスキームにおけるハンギングノード面での高次補間法の提案と実用性

    淺田啓幸, 玉置義治, 久谷雄一, 河合宗司

    第34回数値流体力学シンポジウム　2020/12

  22. Dispersion and dissipation analysis for unphysical modes of high-order discontinuous Galerkin methods

    Hiroyuki Asada

    AIAA Scitech 2020 Forum　2020/01

  23. 高次精度 DG 法におけるエイリアシングの理解

    淺田啓幸

    第33回数値流体力学シンポジウム　2019/11

  24. 高次精度DG法における非物理的モードの挙動

    淺田啓幸

    第51回流体力学講演会/第37回航空宇宙数値シミュレーションシンポジウム　2019/07

  25. A sponge layer for accurate aeroacoustic simulations using high-order discontinuous Galerkin methods

    AIAA Science and Technology Forum (Scitech2019)　2019/01/07

  26. Basic investigations of aeronautics simulations using LES and high-order DG methods

    International Symposium on Transport Phenomenon　2018/10/30

  27. 高次精度DG法を用いた空力音響解析に対する基礎検証

    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シンポジウム　2018/07

  28. 高次精度陰的DG法による空力音響解析

    日本航空宇宙学会北部支部2018 年講演会　2018/03

  29. 自乗量保存型モーダルDG法の提案

    第49回流体力学講演会/第35回航空宇宙数値シミュレーションシンポジウム　2017/06

  30. An attempt to extend split forms to modal discontinuous Galerkin schemes

    Opening Ceremony of the UW-TU : AOS, Poster Session on Composite Materials for Aircraft and Aero Space Engineerin　2017/04

  31. High-order implicit discontinuous Galerkin scheme for unsteady turbulent flows

    55th AIAA Aerospace Science Meeting　2017/01

  32. DG法とSV法によるNASA-CRMの空力解析

    第54回飛行機シンポジウム　2016/10

  33. 非定常乱流を可能とするコンパクトな陰的DG法の提案

    第48回流体力学講演会/第34回航空宇宙数値シミュレーションシンポジウム　2016/07

  34. Requirements of Grid Resolution in Wall-Resolved LES Using High-Order DG Method

    ECCOMAS 2016　2016/06

  35. High-order DG-CRI scheme for unsteady turbulent computations

    Next Generation Transport Aircraft Workshop 2016　2016/02

  36. High-Order Cellwise Relaxation Implicit Discontinuous Galerkin scheme for Unsteady Flow Computations

    54th AIAA Aerospace Science Meeting　2016/01

  37. 高次精度DG法におけるセル緩和型陰解法の乱流統計量への影響

    第29回数値流体力学シンポジウム　2015/12

  38. DG法とSV法によるNASA-CRMの解析

    第53回飛行機シンポジウム　2015/11

  39. 高次精度不連続ガレルキン法を用いた非定常流解析

    第47回流体力学講演会/第33回航空宇宙数値シミュレーションシンポジウム　2015/07

  40. Numerical Technique for High-Order Computation Using Cellwise Relaxation Implicit Discontinuous Galerkin Scheme

    Student presentation at DLR　2015/02

  41. A Fourth Order Accurate Cellwise Relaxation Implicit Discontinuous Galerkin Scheme for Solving RANS Equations

    53rd AIAA Aerospace Science Meeting　2015/01

  42. 空間4次精度非構造格子法による翼まわり圧縮性粘性流体解析

    第27回計算力学講演会　2014/11

  43. 翼まわり定常計算に向けた空間4次精度非構造格子法の構築

    第46回流体力学講演会/第32回航空宇宙数値シミュレーションシンポジウム　2014/07

  44. Improvement of Cellwise Relaxation Implicit Discontinuous Galerkin Scheme

    COMPSAFE2014　2014/04

  45. セル緩和型陰的不連続ガレルキン法の高次精度化と実用化に関する研究

    日本航空宇宙学会北部支部2014 年講演会　2014/03

  46. Improvement of Cellwise Relaxation Implicit Discontinuous Galerkin Scheme

    2014/02

  47. セル緩和型陰的不連続ガレルキン法の高度化

    第45回流体力学講演会/航空宇宙数値シミュレーションシンポジウム2013　2013/07

  48. セル緩和型陰的不連続ガレルキン法による楕円型方程式の高精度離散化手法の研究

    日本航空宇宙学会北部支部2013 年講演会　2013/03

Show all Show first 5

Research Projects 4

  1. 超大規模データから流体制御に有意な因果関係を導くデータ駆動科学的手法の構築

    淺田 啓幸

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 若手研究

    Institution: 東北大学

    2024/04/01 - 2027/03/31

  2. Study of heat sensor for simultaneously measuring multiple physical quantities by computational analysis of unsteady heat-fluid flows

    Ogami Yoshifumi

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

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

    Institution: Ritsumeikan University

    2018/04/01 - 2021/03/31

    More details Close

    The temperature distribution of the gas (e.g., air) in the sensor varies when an acceleration is added to the sensor and/or the sensor is rotated. The values of the acceleration and the rotation speed can be simultaneously obtained by measuring the temperature. In this research, the principle of the simultaneous measurement of the multiple physical quantities and the method for this are studied by computational simulations using a simple circular cylindrical sensor model and a realistic model with complicated structure.

  3. 航空機離着陸時の非定常乱流LESに向けた安定かつ超高次精度な非構造格子法の開発

    淺田 啓幸

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 若手研究

    Institution: 立命館大学

    2019/04/01 - 2020/03/31

    More details Close

    離着陸時の航空機まわり非定常乱流をLESにより高精度にシミュレーションするため，超高次精度DG法の低エイリアシング化（安定化）を目指した．不十分な計算格子数で発生する計算格子エイリアシングに加えて，不十分な数値積分で発生する数値積分エリアシングも新たに考え，それらを個別に削減することを考えた．研究計画では，まず混合積分のアイデアで数値積分エイリアシングの削減を予定していたが，混合積分では二つのエイリアシングのどちらに削減効果があるのか明白にできないと考えた．そこで予定を変更し，計算格子エイリアシングの発生原理を明白にするため，超高次精度DG法に対する理論フーリエ解析を行った．エイリアシングを考慮したDG法の理論フーリエ解析は本研究が初の試みである．1次元正弦波移流問題の数値実験結果を再現することでフーリエ解析結果の妥当性を確認しながら解析を行った．その結果，有限差分法で発生するような基本的なエイリアシング以外にも，高次精度実現のためセル内自由度を導入したが故に発生する，DG法固有の自由度エイリアシングがあると判明した．これは，セル内自由度を導入しているにも関わらず，低波数の波に対しても発生する．また，DG法の全てのモードに対して均一に発生するエイリアシングであることが分かった．数値積分で用いる積分点数の自由度エイリアシングへの影響を検証すると，ほとんど影響がなく数値積分エイリアシングとは関係が薄いことが判明した．すなわち，自由度エイリアシングの低減に混合積分は有効でない．また，自由度エイリアシングの低減方法を1次元正弦波移流問題の範疇で検討したところ，初期条件のモードへの高精度投影により大幅に低減できると分かった．LESでは初期から複雑な流れになることはなく，この方法は実用的でないが，その削減原理をより明らかにすることで実用的なエイリアシング低減方法も可能と言える．

  4. 低騒音な次世代航空機の設計に向けた高精度空力騒音解析

    淺田 啓幸

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 特別研究員奨励費

    Institution: 東北大学

    2016/04/22 - 2018/03/31

    More details Close

    本研究では、高次精度非構造格子法であるdiscontinuous Galerkin (DG)法を用いて、乱流を高精度に予測するlarge eddy simulation (LES)を行い、高精度空力音響解析を実現することで、低騒音な次世代航空機開発への貢献を試みている。このために3つのステップを設け、平成29年度は(2)高精度LES解析実現のための自乗量保存型DG法の構築、(3)航空機まわりの高精度空力音響解析を行った。(2)では、これまで提案されていた自乗量保存型nodal DG法の構築方法を参考にし、自乗量保存型modal DG法の構築を行った。自乗量保存型nodal DG法では差分的な考え方が用いられているが、modal DG法ではこの考え方が容易ではない。そのため、自乗量保存型nodal DG法を有限体積的にフラックスを用いて構築し直し、その知見をmodal DG法へと適用した。その結果、適切なフラックスだけでなく、解析的に導出可能な適切なモード係数を用いることにより自乗量保存が満たされることがわかった。非粘性Taylor-Green渦の解析を通して構築した自乗量保存型modal DG法の性能評価を行ったところ、運動エネルギーの保存が確認できた。(3)では、まず円柱まわりの空力音響解析を通してvalidationを行った。基本的な乱流統計量だけでなく、速度スペクトルや音響を表す圧力スペクトルなども参照解とよく一致した。その後、高揚力装置まわりの解析を行ったところ、境界層の剥離や再付着、乱流遷移などといった特徴的な流れだけでなく、それらにより発生した特徴的な音響についても捉えることができた。しかし、参考にした過去の解析例とは異なる傾向を示した。この原因はスパン方向の計算領域の違いにあることが分かり、今後はより広い計算領域での解析を予定している。

Teaching Experience 3

  1. 数理情報学演習　東北大学

  2. Laboratory Experiment II(Aerospace Engineering)　Tohoku University

  3. Exercises in Computer-AidedProblem Solving　Tohoku University

Works 1

  1. High-fidelity LES around full aircraft configuration (YouTube)

    Hiroyuki Asada, Soshi Kawai

    2021/12/13 -

    Type: Other