Shock Induced Surface Instabilities and Nonlinear Wave Interactions

. We discuss the application of front tracking to the simulation of shock reflections and shock accelerated interfaces. Some key features of the front tracking method are the elimination of numerical diffusion and the reduction of wall heating. In computations of the regular Mach reflection of a shock at an oblique ramp, we see enhanced resolution of the primary waves in the interaction. In addition, tracking allows very precise measurements to be made of the states and location of the Mach triple point. Our computations of the growth rate of a Richtmyer-Meshkov unstable interface are the first numerical results that are in quantitative agreement with experimental results of a shocked air-SF 6 interface. Previous attempts to model the growth rate of the instability have produced values that are almost twice that of the experimental measurements. Moreover, the failure of the impulsive model, and the linear theory from which it is derived, to model experiments correctly is understood in ..