Comparison of two- and three-dimensional simulations of miscible Richtmyer-Meshkov instability with multimode initial conditions

A comparison between two- and three-dimensional large-eddy simulations of the planar Richtmyer-Meshkov instability with multimode initial conditions is made. The three-dimensional calculation achieves a turbulent state where an inertial range of length scales is present after the second shock wave impacts the interface. Grid independence of the mixing width up until the time of reshock is demonstrated through mesh refinement in both two and three dimensions. Quantitative measures of mixing are compared including the mixing width, mixedness, mixed mass, and spectra of velocity and density. A proposed approximate relation for the mixed mass is evaluated in one, two, and three dimensions and is proportional to the product of the mixing width and the mass fraction variance in the layer. The variance of the velocity field and the scalar mass fraction are compared in two and three dimensions and demonstrate large differences in behavior. (C) 2014 AIP Publishing LLC.