Numerical study of high temperature non-equilibrium effects of double-wedge in hypervelocity flow

Abstract

The high temperature non-equilibrium effects of shock wave interaction and shock wave/boundary layer interaction are important issues for hypervelocity flows. The models of thermochemical non-equilibrium gas (TCNEG), thermal non-equilibrium chemical frozen gas (TNCFG), chemical non-equilibrium gas (CNEG), and thermally perfect gas are used to simulate the double-wedge flows with a total enthalpy of 8 MJ/kg in this study. The unsteady two-temperature Naiver-Stokes equations in the laminar and turbulence flows are solved using the finite volume method. For laminar flow, the shock structures and the heat flux peak for TCNEG model at 170 μs are agreed better with the experiment result compared to reference studies. There are different size vortices in the separation zones, which causes the distributions of the wall heat flux oscillate irregularly. The thermal non-equilibrium effects are the most intense near the attached shock and detached shock, and the degree of oxygen dissociation is the strongest in the subsonic zone near the slip-line. For turbulence flow, the shock structures for the four models are close to Edney's IV interaction. The separation shock position for the TNCFG model is the most upstream, and that for the CNEG model is quite different from the TCNEG model. The intensity of the reflected shocks on the back wedge and its nearby shock interaction largely determine the peak values of the heat flux for the four models.