Extended wall-adapting local eddy-viscosity model for the large-eddy simulations of multiscale flows

Abstract

We report on progress made in improving the performance of the well established Wall-Adapting Local Eddy-viscosity (WALE) model in an important class of multiscale flows, namely that of unsteady, massively-separated flows at high Reynolds number. While this model succeeds in capturing the asymptotic near-wall behavior of the eddy viscosity that enters into the formulation of the model for the sub-grid scale correlations, its performance in these flows have proved to be unsatisfactory due to high levels of dissipation leading to poor predictions in the separated wakes. We have sought to improve the performance of this model by combining it with another, the Regularized Variational Multiscale (RVM) model, which better represents the interactions that occur in multiscale flows. This combination, which was implemented in OpenFOAM, was validated against experimental data for the challengingcase of vortex shedding from circular cylinders at high Reynolds number. Distinct improvements over the original model were obtained.