NUMERICAL STUDY ON THE RM INSTABILITY OF A HEAVY-GAS CYLINDER INTERACTED WITH RESHOCK

The evolution of the Richtmyer-Meshkov (RM) instability of a two-dimensional gas cylinder interacted with incident planar shock and reshock is investigated numerically. The procedure VAS2D based on the finite volume method combined with an adaptive mesh refinement is used to effectively capture the wave propagation and interface deformation. The incident planar shock Mach number is 1.2, and the gas cylinder is filled with sulfur hexafluoride (SF₆) surrounded by air, and the shock tube end wall is regarded as a solid wall. In the simulations, the distances from the gas cylinder to the end wall are changed to obtain the influence of the reshock on the gas cylinder shape, the interface scale and circulation variation trend of the evolving interface. It is found that the evolution of the reshock inhomogeneity and the variation of the circulation with time are dependent on the development of the distorted gas cylinder when the reshock arrives. The generation and distribution of the vorticity during the interaction of the reshock with the evolving gas cylinder are different from the case without reshock, which indicates the physical mechanism of the interface evolution under different conditions.