Development of an Unstructured Navier-Stokes Solver for Hypersonic Nonequilibrium Aerothermodynamics

Numerical simulations of a spacecraft at reentry conditions are presented. The fluid at such conditions is modeled as a reacting gas in thermal and chemical nonequilibrium. The reacting gas is modeled using a standard finite rate chemistry model for air. A twotemperature model is used to account for the thermal nonequilibrium effects. The finitevolume method is used to solve the set of differential equations on unstructured meshes. Numerical fluxes between the cells are discretized using a modified Steger-Warming Flux Vector Splitting (FVS) which has low dissipation and is appropriate to calculate boundary layers. The scheme switches back to the original Steger-Warming FVS near shock waves. A point implicit method is used to perform the time march. The numerical results for heat transfer are compared to available experimental data. The influence of the method used to switch between schemes on the results is assessed.