Shear-improved Smagorinsky model for large-eddy simulation of wall-bounded turbulent flows
نویسندگان
چکیده
A shear-improved Smagorinsky model is introduced based on recent results concerning shear effects in wall-bounded turbulence by Toschi et al. (2000). The Smagorinsky eddyviscosity is modified as νT = (Cs∆) (|S|−|〈S〉|): the magnitude of the mean shear |〈S〉| is subtracted to the magnitude of the instantaneous resolved strain-rate tensor |S|; here CS is the standard Smagorinsky constant and ∆ denotes the grid spacing. This subgrid-scale model is tested in large-eddy simulations of plane-channel flows at Reynolds numbers Reτ = 395 and Reτ = 590. First comparisons with the dynamic Smagorinsky model and direct numerical simulations, including mean velocity, turbulent kinetic energy and Reynolds stress profiles, are shown to be extremely satisfactory. The proposed model, in addition of being physically sound, has a low computational cost and possesses a high potentiality of generalization to more complex non-homogeneous turbulent flows.
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