A New Turbulence Model for Large Eddy Simulation

The present - day Large Eddy Simulation models based on the Smagorinsky assumption and the drawbacks of the dynamic calculation of the closure coefficient for the generalised subgrid scale turbulent stress tensor are presented. The relations between numerical scheme conservation property of mass, momentum and kinetic energy and the drawbacks of the dynamic Smagorinsky - type turbulence models are shown. A new turbulence model is proposed. The proposed model: a) is able to take into account the anisotropy of the turbulence; b) remove any balance assumption between the production and dissipation of sub grid scale turbulent kinetic energy; c) is able to eliminate the numerical effects produced by the non conservation a priori of the resolved kinetic energy. New closure relations for the unknown terms of the subgrid scale viscous dissipation balance equation are proposed. The filtered momentum equations are solved by using a sixth order finite difference scheme. The proposed model is tested for a turbulent channel flow at Reynolds numbers (based on friction velocity and channel half-width) ranging from 395 to 2340