Studies of the NS-alpha model using a lid-driven cavity flow
Abstract
The NS-alpha equations have a more compact energy spectrum than the Navier- Stokes equations. Hence, it has been proposed in the literature to use them as a turbulence model. Here we present results from our experience in applying the NS- alpha model to an anisotropic and inhomogeneous flow, namely, a lid-driven cavity flow. It was found that the isotropic NS-alpha model generated excessive backscatter near the lid. Following an LES methodology, where the smoothed velocity is used as the dependent variable, the anisotropic NS-alpha equations were then investigated as a subgrid model. As compared to the isotropic model, the anisotropic model is found to remove the excessive backscatter near the cavity lid, resulting in improved velocity profiles. The ability of the model to correctly reflect the turbulent state of the cavity, and to reproduce the anisotropy in the turbulent stresses near the cavity bottom will be discussed.
- Publication:
-
APS Division of Fluid Dynamics Meeting Abstracts
- Pub Date:
- November 2007
- Bibcode:
- 2007APS..DFD.EE001S