Dynamic Tensorial Eddy Viscosity and Turbulent Stresses

In the theoretical framework provided by an alternative decomposition of the turbulent stresses, a new formalism for their approximation and understanding has been proposed in [1] that spontaneously directs to a tensorial turbulent eddy viscosity. Based on this, new modelling approaches for LES, representing subgrid fluxes for momentum, energy and heat fluxes, based on the second order inertial properties of the grid element are developed. The new model has firstly tested in the case of typical LES benchmark for compressible flow, such as the turbulent channel flow. A numerical simulation of turbulent flows in a more complex geometry using unstructured meshes has been performed, exploiting the properties of the eddy viscosity model based on the inertial tensor of the numerical grid element. The analysis highlights the capability of the model to well reproduce the anisotropic character of the turbulent flows.