Investigation of Surface Roughness Dependence on Rarefied Aerodynamics based on Hypersonic Rarefied Wind Tunnel Measurement and Molecular Dynamics Simulations

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04487
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 24010:Aerospace engineering-related
• Research Institution: Japan Aerospace EXploration Agency
• Principal Investigator: Ozawa Takashi 国立研究開発法人宇宙航空研究開発機構, 研究開発部門, 主任研究開発員 (70567544)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 航空宇宙工学 / 希薄気体力学 / 希薄風洞 / DSMC / MD

Outline of Final Research Achievements

This research aims to develop a measurement system for hypersonic rarefied aerodynamics and study rarefied aerodynamic dependence on surface conditions by carrying out both measurements in the hypersonic rarefied wind tunnel (HRWT) and numerical simulations.
We first carried out numerical analyses for model configuration dependence in HRWT, and we found that the effect of surface accommodation and roughness conditions can be seen by using the flowing (not stagnant) model inside a tube. The measured pressure data were consistent with the numerical results with diffuse surface accommodation conditions. Although it is difficult to demonstrate the effect of actual surface roughness, we are able to estimate the influence of surface conditions by applying micro-structured treatment on surfaces.

Free Research Field

航空宇宙工学

Academic Significance and Societal Importance of the Research Achievements

希薄気体領域の空力特性予測は、これまで粒子数値解析に依存してきており、表面モデル依存性が重要な課題である。本研究は数値解析と実験の双方のアプローチを用いることにより、表面係数依存性・表面微細形状依存性の解明を目指すものであり、世界的に見ても例がなく、重要なデータと知見を得ている。超低軌道衛星や大気吸込型イオンエンジンの開発等の希薄流領域を利用するミッションの実現に向けて、希薄空力特性評価技術の向上は必要不可欠であり、本研究結果はこれらのミッションの実現に寄与すると考えられる。