What is a Subgrid Scale Model?

Large eddy simulation requires closure of the filtered Navier-Stokes equations by modeling the subgrid scale stress tensor using the Boussinesq approximation (see Eqn. 141). A subgrid scale model is required to model the subgrid scale viscosity, . Currently, the Smagorinsky Subgrid Scale model is the only option in STAR-CCM+.