NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Collections About News Help Login
Back to Results
A Lagrangian dynamic subgrid-scale model turbulenceA 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.
Document ID
19950014634
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Meneveau, C. (Johns Hopkins Univ. Baltimore, MD, United States)
Lund, T. S. (Stanford Univ. CA., United States)
Cabot, W. (Stanford Univ. CA., United States)
Date Acquired
September 6, 2013
Publication Date
December 1, 1994
Publication Information
Publication: Stanford Univ., Studying Turbulence Using Numerical Simulation Databases. 5: Proceedings of the 1994 Summer Program
Subject Category
Fluid Mechanics And Heat Transfer
Accession Number
95N21051
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Related Records

There are no records associated with this record.
No Preview Available