Direct numerical simulation of turbulent forced convection in a wavy channel at low and order one Prandtl number

An a priori analysis of the behavior of the simple gradient diffusion model of turbulent heat fluxes is performed in the low Prandtl number, separated flow conditions of the present work. While the low Prandtl number effect can be accounted for by an appropriate selection of the turbulent Prandtl number value to be provided to the model, deviations form the expected behavior of turbulent heat fluxes are seen to occur in the flow separation region and downstream reattachment.