A dynamic mixed subgrid scale model for large eddy simulation on unsructured grids: application to turbulent pipe flows

The paper presents a consistent large eddy simulation (LES) framework which is particularly suited for implicitly filtered LES on unstructured finite volume (FV) codes. From the analysis of the subgrid-scale (SGS) stress tensor arising in this new LES formulation, a novel form of scale-similar SGS model is proposed and combined with a classical eddy viscosityterm. The constants in the resulting mixed model are then computed trough a new, cheaper, dynamic procedure based on a consistent redefinition of the Germano identity within the new LES framework. The dynamic mixed model is implemented in a commercial, unstructured, finite volume solver and numerical tests are performed on the turbulent pipe flow at Reτ = 320−1142, showing the flexibility and improvements of the approach over classical modeling strategies.