COMPUTATIONAL ANALYSIS OF FLOW CHARACTERISTICS OF RE-ENTRY VEHICLE AT LOW ALTITUDE

Re-entry vehicles fly through each layer of the atmosphere with different states during descent to Earth. In this study, we investigate the characteristics of the front bow shock wave and rear irregular wake flow of a model re-entry vehicle in the low-altitude transitional regime using CFD based on Navier-Stokes equations. Five species and seventeen species models is used to describe the reaction that might be present at supersonic and hypersonic speeds. It was shown that bow shock wave occurs farther in low-altitude transitional regimes than in high-altitude rarefied regimes. As altitude changes, the difference in heat flux appears to be greater than that of surface temperature due to the influence of heat energy from chemical reactions. Additionally, through a comparison of wake flows, it was confirmed that at lower altitudes, the irregularities of the boundary layer, separation, recompression, and recirculation flows increased, making the wake flows of the vehicle more irregular.