Shock Interaction with Variable Density Grid Turbulence

Shock tube experiments have studied the effects of initial conditions on Richtmyer-Meskov instability for several decades. Improvements in diagnostics continue to lead to further understanding of the physics of RMI. However, experiments fail to obtain turbulence in a single shock. Reshock experiments aim to reach this turbulent state, but often fall short. This leaves a regime not well studied: turbulent variable density mixing and reshock of turbulent variable-density mixing. This regime may be of importance to mixing in inertial confinement fusion capsules, which have high Atwood numbers and multiple shocks driving the mixing. To study this regime, Los Alamos National Laboratory has implemented a series of experiments in a vertical shock tube. These experiments insert a grid across the shock tube; as the shock accelerated air-SF₆ interface is accelerated, passing through the grid at velocities > 80 m/s, grid turbulence is generated. The reflected shock off the bottom of the shock tube is then used to study shock interaction with a variable density turbulent layer. Updates on the experiments will be presented.