Measurements on the Richtmyer-Meshkov Instability using time-resolved PLIF in a dual-driver vertical shock tube

Experiments on the Richtmyer-Meshkov Instability (RMI) using time-resolved Planar Laser Induced Fluorescence (PLIF) are presented. Experiments utilize a dual-driver vertical shock tube in which controlled-strength shock waves are generated from opposite directions to impact a perturbed interface between air and Sulfur Hexafluoride (SF6). The order of shock arrival and time between shock impacts on the interface can be controlled, and shock strengths are chosen such that the bulk flow is halted after the arrival of the second shock wave. This allows the instability to develop within the frame of a single high-speed video camera which records the experiment. The interface contains multi-modal, random perturbations generated by Faraday resonance using a pair of speakers. The experimental setup has been modified for PLIF, which utilizes the fluorescence of acetone seeded in one of the two gases and excited by a high-speed pulse-burst laser to visualize the flow and obtain concentration measurements. These measurements are then used to obtain the mixing layer growth rate and to quantify molecular mixing.