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A lagrangian dynamic subgrid-scale model turbulence
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Meneveau, C. Cabot, W. Lund, T. S. |
| Copyright Year | 1994 |
| Description | A new formulation of the dynamic subgrid-scale model is tested in which the error associated with the Germano identity is minimized over flow pathlines rather than over directions of statistical homogeneity. This procedure allows the application of the dynamic model with averaging to flows in complex geometries that do not possess homogeneous directions. The characteristic Lagrangian time scale over which the averaging is performed is chosen such that the model is purely dissipative, guaranteeing numerical stability when coupled with the Smagorinsky model. The formulation is tested successfully in forced and decaying isotropic turbulence and in fully developed and transitional channel flow. In homogeneous flows, the results are similar to those of the volume-averaged dynamic model, while in channel flow, the predictions are superior to those of the plane-averaged dynamic model. The relationship between the averaged terms in the model and vortical structures (worms) that appear in the LES is investigated. Computational overhead is kept small (about 10 percent above the CPU requirements of the volume or plane-averaged dynamic model) by using an approximate scheme to advance the Lagrangian tracking through first-order Euler time integration and linear interpolation in space. |
| File Size | 1490198 |
| Page Count | 30 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19950014634 |
| Archival Resource Key | ark:/13960/t4hn05b6j |
| Language | English |
| Publisher Date | 1994-12-01 |
| Access Restriction | Open |
| Subject Keyword | Fluid Mechanics And Heat Transfer Turbulent Flow Computational Fluid Dynamics Energy Spectra Turbulence Models Dynamic Models Isotropic Turbulence Channel Flow Lagrangian Function Turbulent Diffusion Numerical Stability Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
