PIV measurements of the single-mode Richtmyer-Meshkov instability.

Experiments will be presented where a system of two gases of different densities ($A = 0.66$) is impulsively accelerated to produce Richtmeyer-Meshkov (RM) instability. An interface is created by filling the driven section of a 9.8 meter long vertical shock tube with opposing gas flows of air and Sulfur Hexafluoride (SF$_{6}$). The interface forms in the top of the Plexiglas test section where the two gasses meet and exit through two slots. The gases are seeded with $0.3 \mu$m polystyrene Latex spheres. An initial 2-D perturbation in the form of a standing wave of sinusoidal shape is created by oscillating the driven section in the horizontal direction. The interface between the gases is impulsively accelerated by an $M=1.2$ shockwave. One image per experiment is captured with a cooled CCD camera. The image is doubly exposed by a double-pulsed ND-YAG laser and is analyzed using autocorrelation PIV techniques. Results will be presented showing velocity and vorticity distribution in the RM flow.