Implementation of concavity over heat shield of a reentry vehicle in reducing aerodynamic heating

Abstract

Excessive amount of aerodynamic heating is a major issue for all kinds of reentry vehicles. In the present computational study, the concave heat shield modification has been used on the existing Orion CEV design to reduce aerodynamic heating. The investigations have been conducted at three different Mach numbers of 3, 6, and 7 to understand the efficacy of the model from the supersonic to hypersonic range. It has been observed that the use of a concave heat shield helps in reducing the aerodynamic heating of the vehicle particularly at hypersonic speeds, and is found to be more effective as the speed increases. Furthermore, the modification caused a decrease of 6.31%, 6.27%, and 6.22% in the ballistic coefficient for Mach 3, 6, and 7, respectively, indicating an increase in the overall aerodynamic drag of the vehicle. As evident from the ballistic coefficient, a maximum of 6.71% increase in aerodynamic drag has been observed at Mach 3. The shock distance experienced by the vehicle is almost doubled for the modified geometry which eventually leads to higher heat dissipation area and thereby lower aerodynamic heating.