Modeling of the interaction between a turbulent flow and an ablatable material

摘要

During atmosphere reentry the probe heat shield suffers from a significant overheating. Composite materials undergo an ablative process that consumes the heat flux by physico-chemical reactions. Plasma jet experiments on polycrystalline graphite show a structural surface roughness like a scalloped pattern when the flow is turbulent. The goal of this study is to understand the interaction between a turbulent flow and an ablatable material at the smallest turbulent scale (the Kolmogorov scale). To this extent, direct numerical simulation (DNS) software has been developed and investigated. Firstly, in order to guarantee simulated patterns, the computed turbulence has been validated according to well-known results for turbulence decay and near-wall turbulence. Secondly, ablation experimentations have been performed to identify parameters responsible for turbulent roughness appearance.