Wall-Layer Turbulent Heat Transfer Modeling for Perturbed Flows

Abstract

A wall-layer turbulent heat transfer model for the streamwise and wall-normal fluxes based on the Reynolds stresses is proposed. A pre-generated dataset obtained from a direct numerical simulation of a perturbed turbulent channel flow with heat transfer was used. The proposed model is based on a transformation of the Reynolds stresses using the wall-normal gradient of the mean temperature and the streamwise velocity. An a priori comparison of the new model, and different models proposed in the literature based on the standard, the generalized, and the non-linear gradient-diffusion hypothesis, with the direct numerical simulation dataset shows that the model performs well in comparison to these closures. It returns a quite reasonable a priori approximation for the streamwise scalar flux which is frequently under predicted.