Effect of Thermal Ablation at the Fluid-Solid Interface of a Hypersonic Reentry Vehicle in Rarefied Flow Regime
Ahilan Appar, Rakesh Kumar
Abstract
The present work aims to develop a coupled flow-thermal solver to study atmospheric reentry phenomenon in the rarefied regime. Conjugate thermal analysis is performed for a charring ablative material by coupling a 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 two solvers in a loosely coupled manner at certain anchor points along the reentry trajectory. Iterative and non-iterative coupling techniques are studied in this work and discussed. The effect of introducing pyrolysis gas at the interface in a loosely coupled flow-thermal analysis is studied by applying a blowing correction function to the heat flux obtained using iterative method. The results show that the blowing gas has an appreciable effect in reducing the surface heat flux that can significantly impact the TPS design.