A modified selective structure function subgrid-scale model

Abstract

We propose a modified version of the selective structure function (SSF) model originally proposed by David (1993 PhD Thesis National Polytechnic Institute, Grenoble). As compared with the SSF model, the modified selective structure function (MSSF) model respects in a better way the energetic exchanges between the supergrid and the subgrid scales and automatically adjusts itself to the discretization thinness of the most energetic scales. Using the PRICELES industrial code, we first simulate decaying homogeneous isotropic turbulence at high Reynolds number. The MSSF model is shown not to dissipate the supergrid scale energy when the kinetic energy is present at large scale only. It leads to a good prediction of the time decay law and to kinetic energy spectra with a well defined k ^−5/3 spectral range extending up to the cut-off wavenumber. The results of the MSSF model are found to be very close to those obtained with Smagorinsky's dynamic model of Germano et al (1991 Phys. Fluids A 3 1760-5). For low Reynolds number isotropic turbulence, a very satisfactory comparison with the experimental data of Comte-Bellot and Corrsin (1971 J. Fluid Mech. 48 273-337) is obtained. In the turbulent channel flow, the MSSF model was shown to allow for a much better prediction of the friction velocity owing to its less dissipative character in the near-wall region as compared to the SSF model.