Subgrid-scale models for large-eddy simulation that are based on exact series expansions for ltered products are considered. In particular, if the rst two terms are retained, the result is a di usive subgrid term with a tensor di usivity. This tensor is proportional to the rate-of-strain tensor of the large-scale velocity eld. This leads to negative di usion in the stretching directions. Implic...

The behavior of a variational multiscale LES model is studied for flows past bluff bodies. The circular cylinder is studied for a Reynolds 3900. Subgrid scale eddy viscosities of Smagorinsky, Vreman and the WALE model are compared. The vortex induced motion of a spar equipped with strakes and flexible mooring is then computed. The interest of variational multi-scale as compared to usual Large E...

Large eddy simulation of turbulent Rayleigh-Bénard convection was carried out to assess various algebraic viscosity subgrid-scale models: (i) Smagorinsky with Wall-Damping, (ii) Dynamic Smagorinsky, (iii) Wall-Adapting Local Eddy-Viscosity, (iv) Vreman, (v) Mixed-Scale, and (vi) a buoyancy-modified Mixed-Scale model that accounts for the buoyancy effects from subgrid-scales. The last is propose...

Large-eddy simulation is being increasingly used as a means of both predicting the properties of specific turbulence flows and providing flow details which can be used like data to test and refine other turbulenceclosure models. In this paper, some of important background and a formalism of large-eddy simulation from a review article by Marcel Lesieur and Olivier Metais titled “New Trends in La...

A new two-equation Kinetic-Eddy Simulation (KES) model is developed for large-eddy simulation (LES) of wall-bounded high Reynolds number flows. This model solves for the local unresolved kinetic energy and the local length scale. The dissipation of the kinetic energy depends on the length scale, as well as, on the length scale gradient. New terms of subgrid viscous work, subgrid pressure diffus...

An important open question for Large Eddy Simulation (LES) of turbulent ow is whether the subgrid-scales (smaller than) and the associated stresses can be described by universal models. This question is examined in terms of the subgrid dissipation rate, which represents the rate at which large-scale turbulent kinetic energy or scalar uctuations are transferred to, or from, the unresolved scales...