Numerical Study of Shock Interference Patterns for Gas Flows with Thermal Nonequilibrium and Finite-Rate Chemistry

摘要

This work investigates shock interaction mechanisms in inviscid hypervelocity gas flows with thermochemical nonequilibrium over double-wedge geometries using CFD. The SU2 solver has been coupled to the Mutation++ library to simulate these interaction mechanisms for different gas mixtures. A systematic numerical study is performed to evaluate how shock interference patterns differ from Edney's classification when air and CO_2 mixtures are considered. Moreover, the impact of varying the freestream temperature is analysed. Results show that, for a freestream temperature of 57 K, a Type V nine-shock configuration and a Type VI-V transition is identified for air and CO_2 flows, respectively. For a freestream temperature of 300 K, the same Type VI-V transition is obtained for the CO; flow with a slightly different shape, whereas a Type V six-shock configuration is obtained for air. It is concluded that increasing the freestream temperature from 57 K to 300 K has more impact on the extent of thermochemical nonequilibrium of an air flow than of a CO_2 flow and, consequently, on the resulting interaction patterns. Moreover, our study shows for the first time that thermal nonequilibrium is overall stronger for air than for CO_2.