A Comparative CFD Analysis of Aerothermal Behaviour of an Orion-Like Capsule in Different Planetary Atmospheres

Abstract

This paper investigates the atmospheric reentry of an Orion-like space capsule across multiple planetary environments under varying wall temperature conditions. To represent these environments, viscous flow modelling is performed using two different approaches to solve the Reynolds-Averaged Navier–Stokes (RANS) equations. The study focuses on high-altitude aerothermodynamic behaviour over a blunt body in high Mach number flow. The results show that heating characteristics are strongly dependent on the planetary atmosphere and corresponding free-stream conditions. While similar flow assumptions can be applied for Earth and Mars, a significant change in flow behaviour is observed in the case of Titan, despite its comparable atmospheric composition to Earth. This difference is primarily driven by variations in atmospheric density and resulting flow regimes. The findings highlight the importance of accurately selecting free-stream properties and appropriate flow models for predicting aerothermal loads. This work contributes to improving the design and analysis of thermal protection systems for future planetary entry missions.