Near-Wall Models for Improved Heat Transfer Predictions in Channel Flow Applications

Abstract

This work aims to improve the accuracy of the predicted temperature profile in the near-wall region of turbulent boundary layers. It is well known that practical understanding of turbulent boundary layers is central to heat transfer enhancement in many engineering applications. In one case, an eddy viscosity formulation based on a near-wall turbulent kinetic energy function and the van Driest mixing length equation are used. In the second case, the turbulent Prandtl number is not assumed constant but rather is modeled by incorporating improved turbulent Prandtl number relations into existing models. The test case is the fully developed plane channel flow, which is considered to be the simplest and most idealized boundary-layer flow. These new formulations show improved agreement against the temperature profiles of direct numerical simulations of turbulent channel flow versus simulated cases using a commercial computational fluid dynamics package.