Stabilization of a supersonic boundary layer by adding a polyatomic vibrationally excited and dissociating gas
Yu.N. Grigoriev1,2, I.V. Ershov1,2
1Federal Research Center for Information and Computational Technologies, Novosibirsk, Russia
2Novosibirsk State Agrarian University, Novosibirsk, Russia
Keywords: boundary layer model, oscillatory excitation, dissociation, mixture, stabilization
Abstract
Based on a system of gas dynamics equations for a mixture of vibrationally excited chemically reacting molecular gases, the effect of a carbon dioxide additive on the stability of a hypersonic boundary layer of neutral nitrogen on a plate was studied. Calculations were performed for five mixture composition variants. Steady-state flow parameters were calculated using a locally self-similar approximation of the boundary layer equations. Within the framework of linear stability theory, the dependences of the critical Reynolds numbers Reδc and the laminar-turbulent transition Reynolds numbers RexT* on the molar concentration of the additive were obtained. In particular, for a 50% mixture, the relative increase in both criteria compared to the corresponding values for a mixture of perfect gases is approximately 53%. Moreover, the contribution of CO2 dissociation to the shift of the laminar-turbulent transition zone is twice as great as the contribution of vibrational mode relaxation. It is shown that the obtained dependence ofRexT* on the molar concentration of the additive correlates with the corresponding experimental results of Professor H. Hornung's group.
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