The Richtmyer-Meshkov instability by diffracted incident shock waves and reshock

The developments of Richtmyer-Meshkov instability at gas interface subjected to a diffracted incident shock wave of low Mach number and reshock wave have been experimentally studied using the high-speed schlieren photography and laser sheet technique. The motionless and stable interface is formed in a vertical shock tube by using a downward flow of nitrogen(light gas N2) and an upward flow of heavy gas SF6, which meet at the desired interface location and exit from the lateral slots in the test section walls. The interaction yields of shock waves with rigid cylinder is complex, including the primary incident shock, reflected bow shock, Mach shock, slip lines originated from the triple Mach shock. The understanding of interaction of this with interface, will contribute to the knowledge of the perturbation originated from the complex flow. The planar shock wave diffracted over a cylindrical column produces local perturbation at the gas interface. It has been demonstrated that the thickness of the interface grows slowly under the incident shock wave, while spike and bubble are clearly observed upon reshock. Moreover, the interaction between the reshock wave and the boundary layer generates wall vortices, which enhances the development of Turbulence Mixing Zone(TMZ). The reflected rarefaction wave from wall-end also accelerates the development of TMZ.