Pressure-strain and pressure-scalar gradient correlations in variable-density turbulent flows

Abstract

Pressure-containing correlations appearing in balance equations for turbulent stresses and scalar fluxes are studied theoretically. In particular, correlations between the fluctuating pressure and fluctuating strain rate or scalar gradient fluctuations are considered. New forms that differ somewhat from others in the literature are proposed to model these terms. The consequences of the new models are shown to be extreme in flows with highly variable density, such as flames, but the models collapse to accepted models in constant-dens ity flows. Where possible, the models are compared against experiments, and the results are encouraging.