Estimates of stability characteristics of boundary layer on a plate under conditions of vibrational excitation of a gas

The development of two-dimensional subsonic disturbances in a supersonic boundary layer of a vibrationally excited gas on a flat plate was studied on the basis of the linear stability theory. A system of two-temperature gas dynamics including the Landau–Teller relaxation equation used as initial model. The unperturbed flow was described by a selfsimilar boundary layer solution for a perfect gas. In the linearized system of equations the temperature disturbances of the transport coefficients were taken into account. The neutral stability curves for the first and second most unstable modes are calculated. It is shown that for both modes the critical Reynolds numbers at maximum excitation exceed by approximately thirteen percentages the corresponding values for a perfect gas. For independently verification of the direct numerical solution neutral stability curves are also calculated on the basis of the asymptotic approach. It is shown that the thus-calculated neutral stability curves agree well with the results of the numerical solution of the original spectral problem.