Non-uniform volumetric structures in Richtmyer-Meshkov flows

We perform an integrated study of volumetric structures in Richtmyer-Meshkov (RM) flows induced by moderate shocks. Experiments, theoretical analyses, Smoothed Particle Hydrodynamics simulations, and ARES Arbitrary Lagrange Eulerian simulations are employed to analyze RM evolution for fluids with contrast densities in case of moderately small amplitude initial perturbation at the fluid interface. After the shock passage the dynamics of the fluids is a superposition of the background motion and the interfacial mixing, and only a small part of the shock energy is available for interfacial mixing. We find that in the fluid bulk the flow fields are non-uniform at small scales, and the heterogeneous volumetric structures include reverse jets, shock-focusing effects, and local hot spots with the temperature substantially higher than that in the ambient