Bulk turbulent transport and structure in Rayleigh-Taylor, Richtmyer-Meshkov, and variable acceleration instabilities

Directed energy and turbulence structure are shown to be crucial in understanding the growth of self-similar Rayleigh-Taylor and incompressible Richtmyer-Meshkov turbulent mixing zones. Averaging over the mixing zone is used to analyze the response of a modified k-epsilon model and a turbulent two-fluid model. Three different transport regimes are then identified by considering self-similar variable acceleration RT flows (SSVARTs), which appear as promising reference flows for model testing.