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Large-eddy simulations of shear flows. (English) Zbl 0910.76062

Summary: First, we present the general framework of large-eddy simulations (LES), with Smagorinsky’s model. Afterwards Kraichnan’s spectral eddy viscosity is introduced and it is shown how it can be employed for LES purposes in isotropic turbulence. The spectral eddy viscosity is generalized to a spectral eddy diffusivity. We use the nonlocal interaction theory to discuss the backscatter issue, and present a generalization of spectral eddy coefficients. This so-called spectral dynamic model allows the representation of non-developed turbulence in the subgrid scales. Utilization of these spectral models in physical space is envisaged in terms of, respectively, the structure function and hyperviscosity models. Two applications to shear flows are considered, namely to the plane mixing layer and channel flow, with statistical results and information about the topology of coherent vortices and structures.

MSC:

76M25 Other numerical methods (fluid mechanics) (MSC2010)
76F10 Shear flows and turbulence
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