Calculation of Turbulent Wall Jets With an Algebraic Reynolds Stress Model

Abstract

A modified version of the k-ε turbulence model is developed which predicts well the main features of turbulent wall jets. The model relates the turbulent shear stress to the mean velocity gradient, the turbulent kinetic energy k, and the dissipation rate ε by way of the Kolmogorov-Prandtl eddy viscosity relation and determines k and ε from transport equations. The empirical constant in the Kolmogorov-Prandtl relation is replaced by a function which is derived by reducing a model form of the Reynolds stress transport equations to algebraic expressions, retaining the wall damping correction to the pressure-strain model used in these equations. The modified k-ε model is applied to a wall jet in stagnant surroundings as well as to a wall jet in a moving stream, and the predictions are compared with experimental data. The agreement is good with respect to most features of these flows.