lmd_LEGACY1983_abstracts.html

1983 .

C. Basdevant and R. Sadourny. Modelling subgrid scales in numerical simulation of two-dimensional turbulent flows. Journal de Mecanique Theorique et Appliquee Supplement, pages 243-269, 1983. [ bib | ADS link ]

Direct numerical simulation of turbulent, two-dimensional flows requires a mesh size on the order of the dissipation scale, provided that the Re is small enough. On the macroscale, where the turbulent structures are considered to be independent of the deterministic behavior of dissipative microstructures, low resolution models can be used if the statistical properties of subgrid scale forces are incorporated into the mesh. It is shown that a two-dimensional turbulence model with a cut-off wavenumber in the enstrophy cascading range, the subgrid scale model involves only a formulation of the cascade process. Nonlinear diffusion operators, based on heuristic principles, are used in the classical approach, while the intermittency that is present in two-dimensional turbulence requires consideration of spectral slopes significantly steeper than classical theory employs. Consequently, two different techniques for defining a phenomenological model expressing the subgrid scale processes are described.