DOI: 10.1615/TSFP4
LARGE EDDY SIMULATIONS OF ROUND FREE JETS USING EXPLICIT FILTERING WITH/WITHOUT DYNAMIC SMAGORINSKY MODEL
Краткое описание
Large Eddy Simulations (LES) of round free jets at Mach number M = 0.9 with Reynolds numbers over the range 2.5 × 103 ≤ ReD ≤ 4 × 105 are performed using explicit selective/high-order filtering with or without Dynamic Smagorinsky Model (DSM). Flow features as well as turbulent kinetic energy budgets in the turbulent jets are reported. Using filtering alone, the results are independent of the filtering strength, and the effects of the Reynolds number on jet development are successfully calculated, indicating that the effective Reynolds number of the computed flows corresponds to the Reynolds number given by the initial conditions. The contributions of filtering and molecular viscosity to the dissipation are also presented. Using DSM, the jet development shows that the effective flow Reynolds number is artificially decreased, and a large part of the dissipation is supplied by the eddy viscosity, in the same way as a significant part of the dissipation is provided by molecular viscosity at low Reynolds numbers. Moreover the DSM results are not appreciably modified when subgrid-scale kinetic energy is combined with eddy-viscosity.