Subgrid-scale models for large-eddy simulations of compressible wall bounded flows

A comparative assessment of six subgrid-scale models is presented in the case of a compressible plane channel flow over isothermal walls, four of which are based on the recent mixed-scale model. A supersonic and a subsonic case In temporal development at Mach 1.5 and 0.5, respectively, are considered for a Reynolds number equal to 3000, with comparison to the direct numerical simulations (DNS) of Coleman ct al. ( Coleman, G, N., Rim, J, and Moser, R. D., A Numerical Study of Turbulent Supersonic Isothermal-Wall Channel Flow Journal of Fluid Mechanics, Vol. 305, 1995, pp. 159-183) in the first case, and the incompressible DNS of Rim et al. (Kim, J., Moin, P., and Moser, R., Turbulence Statistics in Fully Developed Channel Flow at Low Reynolds Number Journal of Fluid Mechanics, Vol. 177, 1987, pp. 133-166) in the second case. For each Mach number, two grids are considered, with about 20 and 5 times less grid points as in the reference DNS, and the results are globally satisfactory, although not excellent. In particular, the wall friction is globally underestimated by about 10%, both in the subsonic and the supersonic cases. Among the models tested are several original combinations, which vanish at the wall without requiring any damping function. They are found to improve significantly upon the statistics, in particular near the wall.