Large-eddy simulation without filter

An large-eddy simulation (LES) formalism based on sampling operators instead of filters is developed. The major advantage of this approach is that sampling operators commute with the product and their application to nonlinear terms is not at the origin of any closure problem. In absence of filters that smooth out the small scale structures in the flow, the discretization errors in the LES are expected to be important. They must be modelled. The possible confusion between modelling and discretization errors is however avoided since these two effects are identical in the present formalism. A generalized dynamic procedure is proposed for sampling-based LES which allows for model parameter optimization and does not require a detailed analysis of the discretization error. In addition to its interesting mathematical properties for LES, the velocity obtained by a spatial sampling is much closer to experimental probe data than the filtered velocity field.