Numerical study of the slip line instabilities in shock-wavywall reflection

Abstract

The study of shock-induced flow instabilities and turbulent mixing is of great significance in the field of astrophysics and inertial confinement fusion. The reflection of a planar shock on a wavy wall is simulated with the Gas Kinetic Scheme (GKS). The time evolution of shock waves and multi-scale flow structures is accurately captured at different incident Mach number for the wavy walls with different wave-height and wavenumbers. Due to the disturbance from the wavy wall, the triple points spontaneously formed and traverse on the front of the wave. The trajectory of the triple points forms a typical cellular pattern. After each collision of the triple points, the slip lines will shed, and the vortex structure will appear from the baroclinic deposition of vorticity. This baroclinic deposition of vorticity is a different mechanism that includes both Richtmyer-Meshkov process and Kelvin-Helmholtz instability. The analysis of the vorticity transport equations is presented to understand this shock driven slip line instability. Finally, this study provides some references for the future investigation of turbulent mixing.