NUMERICAL INVESTIGATION OF IMPINGEMENT HEAT TRANSFER USING LINEAR AND NONLINEAR TWO-EQUATION TURBULENCE MODELS

Abstract

This article concerns development of a prediction method for turbulent impingement heat transfer. An investigation of a single round unconfined impinging air jet under different flow and geometrical conditions is carried out to assess the performance of linear and nonlinear two-equation turbulence models. The results show that these models may be used for impinging jet heat transfer predictions with reasonable success, but application of an ad hoc realizability constraint is necessary to avoid overprediction of the stagnation zone heat transfer. The constitutive relationship of the nonlinear models is shown to be dominated by the linear part for the present problem. Inclusion of quadratic and cubic level strain terms does not significantly affect predictions and the coupling to streamline curvature appears weak. The major effect of using an anisotropic formulation of the turbulent heat fluxes has been shown to reduce stagnation zone heat transfer rates.