재진입 비행체의 저고도에서의 공력 및 정적 안정성에 관한 전산해석

Abstract

Re-entry vehicles may experience unstable flow during descent to Earth at low altitudes and the flow can negatively affect the stability of the vehicle. In this study, we investigate the characteristics of rear wake flow and frontal shock waves of re-entry vehicles for the angle of attack of 0º to -60º in low altitude transitional regime using a Navier-Stokes code. Five species and the transition SST turbulence model are used to describe the low-altitude flows at subsonic to hypersonic speed. It was shown that recirculation rings are getting bigger at lower altitudes and smaller with increasing angle of attack. By calculating the pitching moment at the center of gravity, the vehicle was shown to be statically stable at a low angle of attack. The angle of attack of neutral static stability decreases as the Mach number increases. Additionally, the aerodynamic center of the vehicle is calculated at each altitude and moves near the vehicle as the Mach number increases.