Unsteady behavior and thermochemical non equilibrium effects in hypersonic double-wedge flows

The paper presents highly detailed two-dimensional numerical simulations of hypersonic nitrogen and air flows around a double wedge, characterized by a complex shock wave/boundary layer interaction (SWBLI). The aim of the study is on one hand to investigate the unsteady behavior of such an interaction and on the other to evaluate thermo-chemical non-equilibrium effects. Two different thermo-physical models have been considered, the classical multi-temperature, or mode approximation, and the state-to-state vibrational kinetics. It is shown that for the geometric configuration under investigation, the occurrence of unsteady periodic behavior depends on the flow conditions and is inhibited in the high enthalpy case. Furthermore, non-equilibrium effects become relevant in the case of high enthalpy flows and discrepancies between the results obtained with the two models are observed.