Hydrodynamic instability at the interface between colliding inhomogeneous mediums

This paper deals with the analysis of the perturbation growth at the interface between the colliding mediums, one of them has an initial perturbation field of density. The main difference of this hydrodynamic instability from the classical Richtmyer Meshkov instability is the nature of the initial disturbance. The analyzed hydrodynamic instability is caused by the initial perturbation of the medium density. The time evolution of interface between two mediums has been studied analytically in nonlinear approximation. The problem has been solved for the third-order corrections to hydrodynamic quantities. Nonlinear interactions cause the appearance of surface sound wave near the contact discontinuity. This wave decreases the growth of the spike velocity. Spike and bubble evolutions have a saturation stage. The numerical calculations confirm the results of the theoretical analysis.