Richtmyer-Meshkov instability studies of a repeatable initial condition

Seen during supernova explosions and in inertial confinement fusion applications, the Richtmyer-Meshkov instability (RMI) is created by a shock wave accelerating fluids of different densities into each other. The vertical shock tube facility at Los Alamos National Laboratory is well-equipped to obtain experimental validation in support of physics-based models of the RMI phenomena. However, the effects of initial interface characteristics on the late time growth of the mixing region remain unclarified from previous experimental and numerical results. To establish a controllable sinusoidal interface between low-density air and high-density SF₆, we crossflow gases over an oscillating splitter plate while using simultaneous particle image velocimetry and planar laser-induced fluorescence for combined measurements of velocity and density fields. We present preliminary quantitative observations of the time evolution of RMI initiated with various periodic perturbations, and continue to improve control of initial conditions at the interface. Using the velocity and density fields from these measurements, we further estimate the turbulence parameters required to initialize a Besnard-Harlow-Rauenzhan turbulence model, greatly improving our ability to model the experiments.