Edney Shock Interactions in High Enthalpy Rarefied Gas Flows

This study aims to computationally model and characterize Edney Type-IV shock–shock interactions using an open-source Navier–Stokes solver within the OpenFOAM framework. Previous numerical investigations have mainly examined such interactions at high Mach numbers under low-enthalpy, rarefied conditions. While previous studies have provided valuable insights into shock interactions under rarefied conditions, their applicability to high-enthalpy regimes with strong thermochemical activity remains limited in the slip-flow regime. The present work addresses this gap by introducing high-enthalpy conditions to enable the modeling of thermochemical nonequilibrium effects in shock interaction behavior within the slip-flow regime with CFD. To do that, two different datasets have been run. The first dataset includes low-enthalpy conditions as a validation step. The simulations are validated against experimental results from the ONERA R5Ch wind tunnel. Secondly, high-enthalpy effects are incorporated to capture the coupled influence of rarefied gas dynamics and thermochemical nonequilibrium by increasing the stagnation enthalpy of the flow. Results show that molecular dissociation and exchange reaction patterns align closely with vibrational temperature distributions. This indicates that energy transfer into vibrational modes plays a critical role in driving reactions under rarefied, high-speed conditions, highlighting the importance of thermochemical nonequilibrium modeling in hypersonic flow simulations.