Model of the boundary layer of a vibrationally excited dissociating gas
Yu.N. Grigoryev1, A.G. Gorobchuk1, I.V. Ershov2
1Federal Research Center of Information and Computational Technologies, Novosibirsk, Russia
2Novosibirsk State Agrarian University, Novosibirsk, Russia
Keywords: boundary layer model, vibrational excitation, dissociation, locally self-similar solutions, numerical method
Abstract
A physical-mathematical model of a plane supersonic boundary layer of a vibrationally excited dissociating gas in the Prandtl approximation is presented. The simplest case of a diatomic gas parameterized according to the data for nitrogen is considered. A number of simplified formulas for calculating the transport coefficients and the dissociation and recombination rates for a molecular-atomic mixture, which are admissible for typical conditions of supersonic and hypersonic boundary layers, are substantiated. Comparative calculations of numerical and locally self-similar solutions of the boundary layer equations on a flat plate for typical conditions of a high-enthalpy wind tunnel and hypersonic flight in the upper atmosphere are performed. It is shown that the atomic concentration profiles calculated on the basis of these approaches differ significantly. In this regard, in order to adequately take into account the effect of chemical reactions in the boundary layer stability calculations, it is necessary to use the profiles of hydrodynamic parameters calculated numerically on the basis of full boundary layer equations. Locally self-similar solutions can serve as initial conditions for numerical calculations.
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