Numerical simulations of interface with different shape accelerated by a planar shock

Abstract

The development of Richtmyer-Meshkov instability on interfaces with different shapes is numerically investigated. The numerical method employs an adaptive unstructured quadrilateral mesh, which can capture the interface evolution very well. Simulations are carried out under the condition of a Mach number of 1.2 and light/heavy (air/ SF6) interfaces. Three shapes are considered in the simulations, i.e., rectangle, ellipse and triangle. The differences in the wave system, generation and distribute of the vorticity and evolution of interfaces are presented and discussed for these three different shapes. The results show that the initial shape of the interface will affect the development of the instability, which will cause the differences in wave patterns, vorticity generation and distribution, and eventually will lead to the different evolution modes. These findings indicate that it may be different to the dominant mechanism of Richtmyer- Meshkov instability on different interface shapes.