Tensorial definition of the eddy viscosity in large eddy simulation of turbulent flows

A new model for the Sub-Grid Scale turbulent stress in the Large Eddy Simulation is proposed, that is based on the definition in tensorial terms of the eddy viscosity. The model employs the Germane identity in order to dynamically evaluating the single required input coefficient and it thus doesn't need any empirical calibration. The eddy viscosity tensorial expression is deduced by removing the widely used isotropy assumption of the high-frequency viscous dissipation. In the paper, the filtered Navier-Stokes equations are discretized on a nonstaggered grid using a finite-volume approach and a fractional step method is employed. It is analysed the accuracy of the employed numerical scheme, and the numerical energy dissipation is compared to the dissipation induced by the proposed turbulence model. The results of the performed numerical simulations are in good agreement with experimental measures.