title: Anomalous Richtmyer-Meshkov fingering in dissipative particle systems.
abstract: We study the fingering instability induced by a shock that propagates across a perturbed interface that separates two types of discrete particles. If collisions between particles conserve energy, then the relative sizes and growth rates of the fingers are similar to those in the analogous shock-induced fingering instability in fluids. However, we show that energy loss during particle collisions, even when very small, causes the qualitative features of the finger growth to be completely opposite to the fluid case. The fingers formed by light particles grow faster and become longer and narrower than the fingers formed by heavy particles. In addition, the finger composed of light particles collapses into an extremely compact, tortuous filament, and diffusive mixing between particle types at the particle scale is heavily suppressed.
authors.affiliation: Department of Mathematics, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
authors.forename: Jonathan J
authors.initials: JJ
authors.lastname: Wylie
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.forename: Xiuxin
authors.initials: X
authors.lastname: Sun