Study on Thermal Protection Performance of Forward-Facing Cavity Structure of Space Vehicle in Rarefied Flow

Numerical simulations of aerothermal performance on the forward-facing cavity structure of the space vehicle in rarefied flow are performed by using the Direct Simulation Monte Carlo(DSMC) method. The heat flux distributions of the outer wall of the nose cone, the side and base wall of the forward-facing cavity are obtained. The influence of different cavity size on the cooling performance of the forward-facing cavity structure is analyzed and compared with the calculation results of the continuous flow. The numerical results show that in rarefied flow, the forward-facing cavity structure can effectively improve the aerothermal environment in the region of the stagnation point of the spacecraft nose cone and significantly reduce the heat flux density at the nose cone. Different from the continuous flow, the maximum value of heat flux of the outer wall of the nose cone and the side and base wall of the forward-facing cavity appear at the tip of the sharp lip. The change of the aspect ratio of the cavity has no obvious effect on the thermal protection efficiency.