Near-Wall Modeling of Turbulent Flow and Heat Transfer Using a Spectral Element CFD Solver

Abstract

In the present work, an equilibrium wall modeling framework is implemented in the high-order spectral element computational fluid dynamics (CFD) solver, Nek5000, for wall-modeled large eddy simulations (WMLES) of wall-bounded turbulent flow and heat transfer. The wall modeling approach is implemented in the implicit LES (ILES) context and is based on an equilibrium algebraic wall-stress model that uses the flow data away from the wall to reconstruct the wall shear stress. The Reichardt law-of-the-wall is used which provides smoothing between the linear and log regions of the boundary layer. In addition, a thermal law-of-the-wall model is implemented to calculate the local wall heat flux. The model implementation and accuracy is validated for a plane channel flow test case comprised of fully developed turbulent flow between two parallel walls at a constant temperature difference, using a wall-resolved LES (WRLES) as the reference solution. The study demonstrates that the implemented wall model can capture the non-dimensional mean streamwise velocity and temperature profiles in the log region with good accuracy. Moreover, the impact of grid resolution on the prediction of mean fluctuations is also investigated.