A proposed modification to the dynamic approach
In this paper a modification related to the scale-invariancy condition, based on a simple dissipation argument coupled with the hypothesis of Chen et al. (J. Fluids Eng. 2005; 127:840-850), is proposed for the dynamic model coefficient evaluation approach. The modification is applied to the Smagorinsky model and used in the calculations of low Reynolds number (Re-tau = 180) channel flow, where the scale-invariancy assumption of the dynamic approach is expected to fail along the wall-normal direction. A detailed analysis of the results is performed for the mean velocity profile, dissipation characteristics, second and higher order statistics, and the energy spectra. The results are compared with the Smagorinsky, the dynamic Smagorinsky, no model, the modification proposed by Meneveau and Lund (Phys. Fluids 1996; 9(12):3932-3934), and the DNS data. The proposed modification yields a better model coefficient profile and shows definitive improvement of the results for all flow statistics considered. Copyright (c) 2007 John Wiley & Sons, Ltd.
dynamic approach channel flow