Combination of Low Reynolds-Number Second Moment Closure Models for Predicting the Turbulent Prandtl Number in Slot Impinging Jet

This paper discusses on improving the prediction of flow and heat transfer in jet impingement through the combination of low Reynolds-number second moment closure turbulence models. A slot impinging jet with the H/W=6 at three different Reynolds numbers 5200, 7800 and 10,400 are numerically analyzed. Three different explicit algebraic heat flux models are applied for predicting turbulent heat fluxes. Numerical results show that the turbulent heat flux model plays an important role in accurately predicting jet impinging heat transfer. The comparisons show that the model of Younis et al. is in reasonable agreement with the available experimental data for predicting the local Nusselt number. Also results show that the turbulent Prandtl can not be assumed as a constant prescribed value. It has been shown that this parameter is varied in the range of 0.5-7.0 from near of the wall to far from it, respectively. The jet Reynolds number affects on predicted turbulent number only in near wall region.