Grid Filter Modeling for Large-Eddy Simulation

Abstract

An interpretation to the use of deconvolution models when used in implicitly filtered large-eddy simulations as a way to approximate the projective grid filter is given. Consequently, a new category of subgrid models, the grid filter models, is defined. This approach gives a theoretical justification to the use of deconvolution models without explicit filtering of the solution and explains how the use of such models can be effective in this context.

This viewpoint also allows to consider a new way of designing the convolution filter which has to approximate the grid filter and therefore a new way of improving such subgrid models. In this framework, a general technique for the approximation of the grid filter associated with any function-based numerical method is proposed. The resulting subgrid model is parameterless, only depends on the mesh used for the large-eddy simulation which is a priori known and vanishes locally if the flow is not turbulent, thereby ensuring the consistency of the model with the Navier-Stokes equations.