激波与不同形状界面作用的数值模拟

该文数值研究了激波与不同形状界面相互作用下的Richtmyer-Meshkov不稳定性发展．数值方法采用自适应的非结构四边形网格来精细刻画界面的演变．在激波Ma=1．2，界面内为sR气体的条件下，通过数值模拟激波与矩形、三角形以及椭圆界面相互作用的过程，分析并对比了这3种形状界面的波系、涡量和界面演变．结果表明，在激波作用下，不同形状流体界面的波系结构是不同的，主要表现在波系的形状以及发展两方面．此外，各种形状界面涡量的产生、分布和大小也有所不同，进而导致各种形状界面演变过程也有一定差异，因此不同形状的流体界面引起的Richtmyer-Meshkov不稳定性有不同的机理．

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

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.