On Type VI–V transition in hypersonic double-wedge flows with thermo-chemical non-equilibrium effects

Abstract

The transition from Type VI to V of inviscid shock interactions on a double-wedge geometry is investigated theoretically and numerically for hypersonic non-equilibrium gas flows. The shock polar method valid for the non-equilibrium gas is developed by introducing a non-equilibrium relaxation length. A preliminary rule for choosing the suitable non-equilibrium relaxation length in different regions of the double-wedge flow is proposed by analyzing the relaxing characteristics. Following this proposal, the shock polar method valid for the non-equilibrium gas can be easily applied to other hypersonic shock interactions. Numerical simulation is used to capture the complete transition from Type VI to V and to obtain the second wedge angle span for this process. The comparison between the theory and the computation indicates that the shock polar method for the non-equilibrium gas can well predict the regional pressure and the critical angle. It is found that the non-equilibrium gas effects lead to a larger second wedge angle for the shock interaction transition and these effects become more significant with a larger Mach number of the inflow. It is interesting that the variation of the transition wedge angle with the Mach number of inflow behaves oppositely for the calorically perfect gas and the non-equilibrium gas.