The Use of Advanced LES Subgrid Scale Models in Combination With Dynamic Grid Adaptation

Abstract

The use of Large Eddy Simulation (LES) is increasingly investigated. However, the LES simulations are computationally demanding, due to the transient nature of the flow computations and the required mesh resolution. Furthermore, the subgrid scale model used for modeling the unresolved flow motions is normally a-priori selected. In an unstructured mesh where the mesh resolution can vary significantly, subgrid scale models should be applied carefully. The present study is aimed to investigate the use of an advanced approach to reduce mesh size by means of a Dynamic Grid Adaptation (DGA) algorithm and to apply a LES subgrid scale model based on local mesh size and flow structure. In this work the DGA algorithm is coupled with the LES turbulence model and made an integral part of the turbulence model. Furthermore, this work has integrated two different LES subgrid scale models which are locally applied to the element in a dynamic manner, dependent on mesh size and flow structure.