Effect of dissociation/vibrational-relaxation coupling on laminar hypersonic boundary layers

High-enthalpy hypersonic boundary layers are subject to a number of finite-rate thermochemical processes, including dissociation, recombination, vibrational relaxation, and ionization. A locally self-similar formulation for laminar hypersonic boundary layers with multicomponent diffusion, finite-rate chemistry, and vibrational nonequilibrium is derived, and numerical solutions are presented in order to evaluate the relative performance of the Park (Park 1989) and CVDV (Marrone and Treanor 1963) two-temperature models. The effects of chemical and thermodynamic nonequilibrium on laminar hypersonic boundary layers are discussed together with the sensitivity of the similarity solutions to the choice of thermochemical model. The similarity solutions are compared with direct numerical simulations (DNS) in order to evaluate the scope of applicability for the self-similar formulation.