Molecular Simulation of Oxygen Reactions with Realistic Carbon and Silica Surfaces at High Temperature

摘要

Recent computational results for gas-surface reactions including atomic level simulations of oxygen-silica recombination and microstructure level simulations of carbon-based ablative surfaces are summarized. Atomic level calculations of oxygen-silica reactions show the main recombination mechanism to be non-activated (associated with no energy barrier). This is in contradiction to current empirical models fit to limited experimental data. For ablative porous and non-porous TPS, where complex microstructure is important, the capability to image a real material with micron scale resolution via x-ray micro-tomography, triangulate the surface, and directly simulate the gas-surface interaction with direct simulation Monte Carlo (DSMC) is demonstrated.