Aerothermodynamic analysis of reentry flows with coupled ablation

A study of graphite ablation in reentry flows is carried out by a fully-coupled surface ablation approach integrated with a two-dimensional axisymmetric Navier-Stokes solver. The gas-surface interaction model is based on both chemical equilibrium and finite-rate ablation modeling and can account for both surface oxidation and sublimation. The surface temperature is obtained from the steady-state ablation approximation. This numerical procedure can predict aerothermal heating, chemical species concentrations, and carbon material ablation rate over the heat-shield surface of reentry vehicles. Two dimensional axi-symmetric simulations have been performed to numerically reproduce the ablation of a graphite sphere-cone for which literature data are available from testing performed in the Interaction Heating Facility at the NASA Ames Research Center. The freestream conditions of the selected test case are typical for Earth reentry from a planetary mission. The predicted ablation rate and surface temperature assuming frozen chemistry in the flow show a good agreement with the available experimental data. The agreement is further improved by the use of finite-rate ablation modeling. © 2011 by Daniele Bianchi.