Spectral Behavior of Various Subgrid-Scale Models in LES at Very High Reynolds Number

Abstract

AbstractThis study investigates the capabilities of various recent subgrid-scale (SGS) models (the so-called “multiscale” models) for large-eddy simulation (LES), used either in a vortex-in-cell (VIC) method or in a pseudo-spectral (PS) method, and their applicability to the simulation of decaying homogeneous isotropic turbulence (HIT) in the limit of very high Reynolds number (i.e. LES on a large grid and where the molecular viscosity dissipation is negligible compared to the SGS dissipation). The proper coefficient value for each model investigated was obtained by a calibration performed in an earlier study. Various large grid resolutions (1283, 2563 and 5123) are used to compare and to indeed obtain the asymptotic spectral behavior of each model. We are then able to emphasize the behavior of the models, that is not necessarily observable in “small” LES (i.e. in LES at moderate Reynolds number and/or using a smaller mesh). In particular, we show that the multiscale models perform significantly better than the Smagorinsky model: a much wider inertial range is obtained.KeywordsLarge-eddy simulationSubgrid-scale modellingMultiscale modellingHigh Reynolds number flowsSpectral behaviorEffective viscosityHyper-viscosityDecaying homogeneous isotropic turbulenceLagrangian methodsVortex particle methodVortex-in-cell methodSpectral method