Computational Analysis of Arc-Jet Stagnation Tests Including Ablation and Shape Change

Abstract

Coupled fluid-material response analyses of arc-jet stagnation tests conducted in a NASA Ames Research Center arc-jet facility are considered. The fluid analysis includes computational Navier-Stokes simulations of the nonequilibrium flowfield in the facility nozzle and test box as well as the flowfield over the models. The material response analysis includes simulation of two-dimensional surface ablation and internal heat conduction, thermal decomposition, and pyrolysis gas flow. For ablating test articles including shape change, the material response and fluid analyses are coupled to take into account changes in surface heat flux and pressure distributions with shape. The ablating material used in these arc-jet tests was a phenolic impregnated carbon ablator. Computational predictions of surface recession, shape change, and material response are compared with the experimental measurements.