Viscous shock-layer study of thermochemical nonequilibrium

A two-temperature, viscous shock-layer (VSL) technique to analyze low-density (slip) effects and vibrational and electronic nonequilibrium for an Ii-species airflow is presented, This formulation employs recently developed physical models, detailed transport and thermodynamic properties, and body and shock-slip conditions for multicomponent mixtures. Presently obtained results reproduce examined reentry flight data acid numerical calculations with a good degree of accuracy over a wide range of conditions, validating its use for the calculation of low-to-high density flows. Detailed stagnation-region calculations along the trajectory of a proposed single-stage-to-orbit vehicle show significant vibrational and electronic nonequilibrium and slip effects at the highest considered altitude of 85 km. The combined effects of thermal nonequilibrium and slip lower the stagnation-point heating by about 24% at this altitude, These effects are negligible on surface quantities at 55 km altitude, At this altitude, however, the chemical nonequilibrium effects lower the stagnation heating obtained from chemical equilibrium calculations by about 21% for the Shuttle-like surface. The results provided here demonstrate the use of the VSL technique as a fast calculation procedure in a conceptual and preliminary design process, requiring sensitivity analysis and rapid reanalysis.