Model Development for Dissipation Terms in Reynolds Stress Equations.

Abstract

This paper presents an anisotropic dissipation term modeling for the Reynolds stress transport equation, and presents a comparison with Direct Numerical Simulation (DNS) data for three different flow systems. In the present model, the anisotropic tensor of the dissipation term is evaluated using three algebraic expressions, eSij, eRij and eWij. eSij represents the effects of only fluctuating velocity, and constitutes the anisotropic tensor of Reynolds stress. The term eRij includes the effects of the mean velocity gradient tensor in addition to that of fluctuating velocity. eWij is analogous to the wall term in the redistribution term for Reynolds stress equations, and reproduces near-wall behavior of the dissipation term. The present model predicts the anisotropic tensor of the dissipation term with good accuracy with respect to diagonal components. However, for non-diagonal components, the predictions are not accurate enough for all systems. Some improvements are necessary for expression of model functions.