State-Resolved Transport Properties of Electronically Excited High-Temperature Flows Behind Strong Shock Waves

Abstract

In the present study, a theoretical model of state-resolved transport coefficients in electronically and vibrationally excited ionized gas mixtures is developed. High-temperature chemically reacting flows of a five-component partially ionized mixture ${N}_2/N/{N}_2^{+}/{N}^{+}/{e}^{-}$ are considered in the state-to-state approach. Rotational, vibrational, and electronic states of molecular species as well as electronic degrees of freedom of atoms, both neutral and ionized, are taken into account. Nonequilibrium reactions of ionization, dissociation, and transitions of electronic and vibrational energy are included in the kinetic scheme. The developed model is applied for evaluating transport properties in strongly nonequilibrium flows behind the plane shock wave under conditions characteristic for the spacecraft reentry from an interplanetary flight (Hermes and Fire II experiments). The range of temperature and the distance behind the shock where the contribution of electronic and vibrational degrees of freedom to the flow parameters is of importance are indicated, and the effect of vibrational and electronic excitation on transport coefficients is analyzed.