Modeling the "rapid" part of the velocity/pressure-gradient correlation in inhomogeneous turbulent flows

Abstract

A new model for the "rapid" part of the velocity/pressure-gradient correlation in the Reynolds averaged Navier-Stokes equations is suggested. It is shown that in an inhomogeneous incompressible turbulent flow, the model that is linear in the Reynolds stresses should include two model coefficients. A functional form of the coefficients is analyzed in some extreme turbulence states. As demonstrated, the proposed model reduces to the standard linear pressure-strain model in homogeneous turbulence and can satisfy realizability conditions provided the coefficients are functions of the mean velocity gradients and the Reynolds stresses. In an inhomogeneous turbulent flow, coefficients should depend on parameters directly related to inhomogeneous effects. The model is validated using direct numerical simulation data from two flows: the plane wake and the plane mixing layer.