A Modified Dynamic Subgrid Scale Stress Model Using Vorticity in the Constitutive Relation

摘要

The conventional dynamic model of Germano et al (Phys. Fluids A, 3, 1760-1765, 1991) and Lilly (Phys. Fluids A, 4, pp.633-635, 1992) relies on information from the resolved strain rate tensor to calibrate the model coefficient. In the research presented in this paper, the conventional dynamic model has been modified to use both the resolved strain rate and vorticity tensors. Turbulent Couette flow has been used to validate the modified modelling approach. The Reynolds number tested is Re = 4762 (based on one half of the velocity difference between the two plates and the channel width). Comparisons are made to the standard model formulation in terms of statistical and instantaneous turbulent characteristics. The relative alignment between the instantaneous values of the predicted SGS stress tensors for the modified and standard models has also been examined.