‘‘Breakthrough’’ via dipolar-vortex/jet formation in shock-accelerated density-stratified layers

Convective ‘‘breakthrough’’ after an inclined planar light fluid layer is struck by a shock wave is observed and quantified. The results of direct numerical simulations are interpreted and a convective breakthrough time tb is quantified. Initially, vorticity of opposite sign is deposited on each interface of the layer. Breakthrough occurs when these vortex regions approach and ‘‘bind’’ into a dipolar vortex (or jet head) that moves away from the wall. Variations of tb with Mach number of the incoming shock waves are given.