The multiscale formulation of large eddy simulation: Decay of homogeneous isotropic turbulence

The variational multiscale method is applied to the large eddy simulation ( LES) of homogeneous, isotropic flows and compared with the classical Smagor insky model, the dynamic Smagorinsky model, and direct numerical simulation (DNS) data. Overall, the multiscale method is in better agreement with the DNS data than both the Smagorinsky model and the dynamic Smagorinsky model . The results are somewhat remarkable when one realizes that the multiscale method is almost identical to the Smagorinsky model (the least accurate mo del!) except for removal of the eddy viscosity from a very small percentage of the lowest modes. (C) 2001 American Institute of Physics.