Comparison of Surface Chemistry Models for the Calculation of Refractive Index Along Hypersonic Vehicle

In this paper we compare the role of three surface chemistry models of hypersonic ablation on the mass flux from the ablating surface and corresponding changes in the refractive index field. To predict the concentrations of ablative products, we simulate hypersonic flow over the RAM-C-II vehicle at Mach 24.3, implementing the finite rate gas-surface reactions as a boundary condition producing surface-normal mass flux. Simulations results are used to compare various chemistry models and their effect on near-surface species concentrations, the refractive index field, and other gas-phase properties near the ablative surface to inform future experiments validating these models.