Statistical analysis of inhomogeneous RMI in the half-height shock tube problem

A detailed statistical analysis of the interaction of a shock with a rectangular shaped SF6 cylinder (half-height shock tube) is performed using high-resolution numerical simulations. The flow configuration consists of a stationary block of 2 stably stratified fluid layers, air and SF6, undergoing sudden acceleration from a Mach 1.26 shock and eventually transitioning to turbulence. The setup is consistent with previously published experimental data. The problem provides a setup in which to study Richtmyer-Meshkov instability (RMI) with two inhomogeneous directions, as well as its interaction with Kelvin-Helmholtz instability. The simulated time window includes the subsequent reshock; during this time prevalent second order moments are tracked, as well as mixing statistics. Specifically, the effect of initial conditions on the flow behaviour is studied, as well as convergence trends of the budgets for high-order numerics. Available experimental data are in excellent agreement with current results.