Thermochemical Modeling in Hypersonic Reactive Flow Behind Strong Shock Wave

In this study, a one-dimensional post-normal shock solver in hypersonic ionized air flow was developed to study the effect of the physical-chemical phenomena that occur at high temperature. To simulate this case, the upstream air flow is considered with 2 species (21% of O₂ and 79% of N₂). Behind the shock wave, the Park’s chemical kinetics model with 11 species (O₂, N₂, NO, O₂⁺, N₂⁺, NO⁺, O, N, O⁺, N⁺, e⁻) and 49 chemical reactions is used. The vibration-dissociation coupling is taken into account according to the Park’s model for which the activation temperature of the dissociation reactions is \(T_{a} = T^{q} T_{v}^{1 - q}\). The energy exchange model between translation modes and vibration modes is described by the Landau-Teller formula where the species relaxation time is based on the Millikan-White formula, including Park’s high-temperature correction. The numerical model of the flows governed by the Euler equations supplemented by the equations of the chemical kinetics and the system of equations obtained is discretized by the finite difference method, good agreement between the relaxation zone obtained and those obtained by Panesi for the two trajectory points corresponding to t = 1634 s and t = 1643 s of the Fire II re-entry vehicle.