Richtmyer-Meshkov growth of a granular layer

This paper explores the mechanism responsible for the growth of Richtmyer-Meshkov instability in the novel context of the impulsive acceleration of a granular layer. With the classical instability, when a density interface is impulsively accelerating towards the medium with a lower density, the phase of interfacial perturbations is reversed and the deposited kinetic energy leads to growth of the perturbations. The higher density medium forms ``spikes'' as it penetrates into the lower density medium, while the lower density medium forms ``bubbles'' as it penetrates into the denser medium. Simple laboratory experiments are used to demonstrate that this Richtmyer-Meshkov growth mechanism can act on the surface of a granular layer, forming structures reminiscent of the classical case. This happens despite the fundamental differences in the way stresses are communicated.