Modifications for an explicit algebraic stress model

An extension of the explicit algebraic stress model, developed by Gatski and Speziale [Gatski TB, Speziale CG. On the explicit algebraic stress models for complex turbulent flows. Journal of Fluid Mechanics 1993; 254: 59-78] is proposed. The extension implicates some essential characteristics of second-order closure models. The strain-dependent coefficients are modified, resulting in an alleviation of the numerical instabilities involved in the model. A new near-wall damping function f mu in the eddy viscosity relation is introduced. To enhance dissipation in near-wall regions, the model constant C-epsilon1 is modified and an extra positive source term is included in the dissipation equation. In addition, a realizable time scale is incorporated to remove the wall singularity. Computed results show that the modified Gatski-Speziale (MGS) model predictions are in better agreement with the direct numerical simulation (DNS) and experimental data than those of the original Gatski-Speziale (OGS) model. Copyright (C) 2001 John Wiley & Sons, Ltd.