Assessment of a shear-improved subgrid stress closure for turbulent channel flows

Abstract

A subgrid-scale model pertaining to Large Eddy Simulation (LES) was developed by modifying the standard Smagorinsky model in order to take into account the inhomogeneities of the mean flow. According to this model, the magnitude of mean strain-rate is subtracted from the magnitude of the resolved strain-rate tensor for the calculation of eddy-viscosity. In this work, we perform large eddy simulation of turbulent channel flows at low and moderate Reynolds numbers. The predicted results compare well with the DNS data and results due to dynamic LES closure. The focus of this study has been on the assessment of capabilities of the model pertaining to the description of flow physics for the Reynolds numbers of interest. Also, the results are intended to establish the dominant effects of shear-length-scale near the wall. The simulations highlight other statistical features and turbulence characteristics too in order to broaden the applicability of the model.