Large-Eddy Simulation of Richtmyer-Meshkov Instability

Abstract

We present results from large-eddy simulations (LES) of three-dimensional Richtmyer-Meshkov (RM) instability in a rectangular tube with reshock off the tube endwall. A hybrid numerical method is used that is shock capturing but which reverts to a centered scheme with low numerical viscosity in regions of smooth flow. The subgrid-scale (SGS) model is the stretched-vortex (SV) model [1]. The shock strength, tube geometry, gas composition, initial conditions and initial interface disturbance were tailored to the experimental conditions of Vetter & Sturtevant [2] with shock Mach number M_s = 1.5, density ratio r = 5, and constituent gases air and SF_6. Use of the SV SGS model allows continuation of radial velocity spectra in the center-plane of the mixing layer, to subgrid scales, including the effect of anisotropy and self-consistent calculation of the viscous cutoff scale.