‘Single mode’ Richtmeyer-Meshkov experiments are studied using the shock tube. Long wavelength perturbations are created using a stepper motor to gently oscillate the flexible shock tube, creating standing waves. This method of agitation results in 1.5, 2.5 or 3.5 waves being generated across the shock tube width. When the shock wave impacts the interface, the interface is in the shape of a two-dimensional sinusoidal wave, which becomes the initial perturbation for the experiment.
Experiments are visualized using Planar Laser Induced Fluorescence (PLIF), using acetone as the tracer and an ultraviolet Nd-YAG laser.
Scale diagram demonstrating the overall length of the shock tube, and the test section and visualization optics. The length of the test section maximizes the amount of time before re-shock occurs, while the large driver section delays the onset of the reflected expansion wave.
The Experimental Fluid Mechanics and Instability Laboratory
Aerospace and Mechanical Engineering Department at University of Arizona