Conjugate flow-thermal analysis of a hypersonic reentry vehicle in the rarefied flow regime

Abstract

A conjugate thermal analysis is performed for a charring ablative material by coupling an in-house direct simulation Monte Carlo flow solver with an in-house material thermal response solver at the fluid–solid interface. The coupling is achieved by exchanging and updating the interface properties (convective heat flux and wall temperature) between the flow and thermal solvers at certain anchor points along the reentry trajectory. Iterative and non-iterative coupling techniques are studied in this work and discussed. In-house flow-thermal code is validated by comparing surface heat flux and temperature variation with those obtained from an open-source code, Stochastic PArallel Rarefied-gas Time-accurate Analyzer, from Sandia National Laboratories, USA. The effect of introducing pyrolysis gas at the interface in the flow-thermal analysis is studied by applying a blowing correction function in an iterative manner. The effect of surface recession is also studied by enabling material degradation due to thermal ablation.