Flow Instability: Richtmyer-Meshkov and Pulsating Flows

Time resolved planar laser induced fluorescence experiments on the Richtmyer-Meshkov instability (RMI) are presented. Experiments are conducted in a vertical dual-driver shock tube with air and sulfur hexafluoride separated by a multi-modal perturbed interface. The shock tube has capabilities for variable shock strengths and shock arrival times of the two generated shock waves, allowing for adjustable shock arrival order and the halting of bulk velocity after the passage of the second shock wave. Visualization of the instability development utilizes the fluorescence of acetone, seeded in the light gas (air), which is excited by a high-speed pulse burst laser. Development of the instability is captured using a single high-speed camera. An additional high-speed camera is used with a fused silica cuvette to reference the pure gas-acetone mixture for image calibration allowing the light gas mole fraction to be obtained. Calibrated images are used to obtain the mixing layer growth rate along with other mixing metrics which are presented.