Hyperviscosity and Vorticity-Based Models for Subgrid Scale Modeling

Large-eddy simulations corresponding to the decaying isotropic turbulence experiment of Comte-Bellot and Corrsin are performed, using a pseudo-spectral code that incorporates four models: viscosity and hyperviscosity types, each implemented for both the subgrid scale stress tensor and the subgrid scale force. Two 1/T scalings are also considered for the viscosity amplitude. The dynamic procedure is extended to the four models and is tested. Results are obtained with and without this procedure and for both scalings. The main conclusions are: (a) the two viscosity models perform equally well; (b) the Kolmogorov scaling performs as well as the Smagorinsky scaling, yet it is computationally more efficient; (c) in the dynamic procedure, there is a fairly wide range of test to grid filter ratios which produces results insensitive to this ratio; and (d) the hyperviscosity models lead to energy decay curves that follow the experimental data as well as the usual viscosity models.