はやぶさ型再突入カプセルの空力安定性に関する数値解析

抄録

Dynamic instability of Hayabusa-type reentry capsule, which is one of the severe problems during atmospheric reentry, was observed in transonic and subsonic regimes. To investigate aerodynamic instability, numerical analysis of flow fields around the capsule was carried out for a case of freestream Mach number of 1.1. In this analysis, large eddy simulation (LES) technique was performed and the standard Smagorinsky model was applied. According to results of the relation between angle of attack and pitching moment coefficient (Cm), it was clarified that the higher frequency component of Cm behavior, which is attributed to turbulence of the wake, is important for aerodynamic instability. Therefore, it was indicated that detail investigation for turbulence fluctuation is necessary.