Study on adjoint global stability analysis method for innovative aerodynamic design technology

• Project/Area Number: 16K18312
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Aerospace engineering
• Research Institution: Japan Aerospace EXploration Agency
• Principal Investigator: Ohmichi Yuya 国立研究開発法人宇宙航空研究開発機構, 航空技術部門, 研究開発員 (40733168)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000); Fiscal Year 2018: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2017: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2016: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
• Keywords: 非定常空気力学 / 圧縮性流体 / 全体安定性 / 随伴解析 / 数値流体力学 / 固有値解析 / 空力設計 / 全体安定性解析

Outline of Final Research Achievements

We developed the adjoint global stability analysis method (Adjoint GLSA) as an effective analysis method for control of unsteady flow fields and showed its effectiveness. The formulation of the adjoint equation and the appropriate boundary conditions are derived, and verified for a two-dimensional flow around a circular cylinder and a cavity flow. In addition, it was clarified that the sensitivity region effective for controlling each of growth rate and frequency of a target unstable mode can be specified by reviewing the definition of sensitivity function. Furthermore, the proposed method is applied to the analysis of vortex breakdown phenomena of a swirling jet, and the unstable mode that causes the vortex breakdown and its sensitivity region are clarified. We demonstrated that unstable modes that cause vortex breakdown can be suppressed or amplified by adding control to the flow field based on the obtained sensitivity region.

Academic Significance and Societal Importance of the Research Achievements

提案手法が確立されることで，今後の非定常空力設計法は，これまでの定性的な考察に基づく設計から定量的な指標に基づく設計に変わり，それにより実験・数値解析の回数削減，個々の条件に応じた細やかな最適化などが可能になると期待される．

Research Products

• [Journal Article] Compressibility effects on the first global instability mode of the vortex formed in a regularized lid-driven cavity flow (2017)
  • Author(s): Yuya Ohmichi and Kojiro Suzuki
  • Journal Title: Computers and Fluids Volume: 145 Pages: 1-7
  • DOI: 10.1016/j.compfluid.2016.12.008
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] Numerical method for adjoint global stability analysis of compressible flows based on matrix-free approach (2018)
  • Author(s): Yuya Ohmichi, Kento Yamada
  • Organizer: 71st Annual Meeting of the APS Division of Fluid Dynamics
  • Int'l Joint Research
• [Presentation] Global Stability Analysis of Vortex Breakdown in Misaligned Compressible Swirling Jet (2018)
  • Author(s): Kento Yamada, Yuya Ohmichi, Kojiro Suzuki
  • Organizer: 71st Annual Meeting of the APS Division of Fluid Dynamics
  • Int'l Joint Research
• [Presentation] 随伴方程式に基づく3次元全体安定性感度解析法の開発 (2017)
  • Author(s): 大道勇哉、山田健翔
  • Organizer: 第31回数値流体力学シンポジウム
• [Presentation] 旋回噴流中の渦崩壊現象の全体線形安定性解析 (2017)
  • Author(s): 山田健翔、大道勇哉、鈴木宏二郎
  • Organizer: 第31回数値流体力学シンポジウム