Subgrid-scale models for compressible large-eddy simulations

An a priori study of subgrid-scale (SGS) models for the unclosed terms in t he energy equation is carried out using the flow field obtained from the di rect simulation of homogeneous isotropic turbulence. Scale-similar models i nvolve multiple filtering operations to identify the smallest resolved scal es that have been shown to be the most active in the interaction with the u nresolved SGSs. In the present study these models are found to give more ac curate prediction of the SGS stresses and heat fluxes than eddy-viscosity a nd eddy-diffusivity models, as well as improved predictions of the SGS turb ulent diffusion, SGS viscous dissipation, and SGS viscous diffusion.