Simulations of turbulent impinging jet heat transfer for different nozzle configurations using Reynolds averaged governing equations and two-equation turbulence models have been conducted. The considered nozzle configurations are a square-edged orifice and a pipe exit. The results for a jet Reynolds number of 10000 and dimensionless nozzle-to-plate distance of 2 show that the heat transfer is well predicted for the pipe configuration but underpredicted for the orifice. The disagreement may be partly explained by underprediction of turbulence in the stagnation region and inaccurate treatment of the wall jet boundary layer transition. An investigation of the local heat transfer distribution for the orifice reveals two local maxima. These are related to an accelerating laminar boundary layer and the transition process of the wall jet, respectively, for the calculations. The application of a realizability constraint on the models leads to reduced turbulence levels, not only in the stagnation region, but also in the throttled flow of the orifice configuration. This improves the prediction of heat transfer and nozzle exit turbulence levels significantly.

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