Reformulation of a two-equation model for the turbulent heat transfer

Abstract

In this paper a model for the turbulent heat transport is developed. The model is based on equations proposed by Nagano and reformulated by the introduction of a specific dissipation rate. Closure coefficients for destruction source terms are derived by assuming a constant time-scale ratio for thermal and velocity fluctuations in homogenous decaying turbulence. Production modelling constants are calibrated in the thermal mixing layer and flat plate viscous boundary layer. The introduction of a specific dissipation rate makes the use of a wall damping function unnecessary. This is advantageous in separated flows. Simulation results of the backward facing step show a more accurate prediction of heat transfer coefficient compared to constant turbulent Prandtl number calculation. The model has been calibrated and applied with the Menter-SST model .