Numerical simulation of electronic-electron energy nonequilibrium in high speed and high temperature flowfields

High speed and high temperature flowfields around several configurations are numerically investigated using different multi-temperature models and an 11-species finite rate chemical reaction model. The flowfields are computed by a multi-block finite volume CFD code. The three-temperature model including the process of electronic-electron nonequilibrium, together with the two-temperature model based on equilibrium electronic-electron state, are incorporated into the code. For the case of sphere ballistic range experiment, it is found that the shock standoff distance is not affected by the electronic-electron nonequilibrium. Numerical results of four flight condition for RAM-C II aircraft indicate that the distributions of electron number density predicted by the two multi-temperature models vary in a similar trend, whose values are in the same order of magnitude. Both results show good agreements with flight experimental data. The three-temperature model is capable of providing more accurate results than the two-temperature model. Numerical results of the FIRE II case yield similar distributions of surface heat flux by utilizing the three-temperature model and the two-temperature model, respectively.