Modeling the Effects of Combustion on Reshocked Richtmyer−Meshkov Instability-Induced Turbulent Mixing

The effects of heat release and combustion processes on integral scale quantities (such as mixing layer width and molecular mixing) and turbulent quantities (such as turbulent kinetic energy and turbulent viscosity) are investigated using one-dimensional Reynolds-averaged Navier−Stokes simulations using a recently proposed four-equation mechanical/scalar turbulence model [Schilling and Mueschke, Physical Review E 96, 063111 (2017)] augmented by the b PDF model to close the mean reaction rates in the species mean mass fraction equations. Quantities are compared for a nonreacting and reacting reshocked Richtmyer−Meshkov instability with a single-step reaction to quantitatively evaluate the effects of combustion on the hydrodynamic evolution. Comparisons of quantities are presented for a hierarchy of increasingly more complete and accurate models for the mean reaction rates, which also include the effects of temperature fluctuations. In addition, the budgets of the mean and turbulent transport equations are compared between the nonreacting and reacting cases to elucidate the mechanisms affecting the hydrodynamic evolution.