Winckelmans, Grégoire
[UCL]
Lund, T.S.
[Stanford University]
Carati, Daniele
[ULB]
Wray, A.A.
[Nasa Ames Research Center]
Subgrid-scale models for Large Eddy Simulation (LES) in both the velocity-pressure and the vorticity-velocity formulations were evaluated and compared in a priori tests using spectral Direct Numerical Simulation (DNS) databases of isotropic turbulence: 128(exp 3) DNS of forced turbulence (Re(sub(lambda))=95.8) filtered, using the sharp cutoff filter, to both 32(exp 3) and 16(exp 3) synthetic LES fields; 512(exp 3) DNS of decaying turbulence (Re(sub(Lambda))=63.5) filtered to both 64(exp 3) and 32(exp 3) LES fields. Gaussian and top-hat filters were also used with the 128(exp 3) database. Different LES models were evaluated for each formulation: eddy-viscosity models, hyper eddy-viscosity models, mixed models, and scale-similarity models. Correlations between exact versus modeled subgrid-scale quantities were measured at three levels: tensor (traceless), vector (solenoidal 'force'), and scalar (dissipation) levels, and for both cases of uniform and variable coefficient(s). Different choices for the 1/T scaling appearing in the eddy-viscosity were also evaluated. It was found that the models for the vorticity-velocity formulation produce higher correlations with the filtered DNS data than their counterpart in the velocity-pressure formulation. It was also found that the hyper eddy-viscosity model performs better than the eddy viscosity model, in both formulations.
Bibliographic reference |
Winckelmans, Grégoire ; Lund, T.S. ; Carati, Daniele ; Wray, A.A.. A priori testing of subgrid-scale models for the velocity-pressure and vorticity-velocity formulations.Center for Turbulence Research Summer Programm 1996In: Nasa Technical Report Server (NTRS), Studying Turbulence Using Numerical Simulation Databases, 1996, p. 309-328 |
Permanent URL |
http://hdl.handle.net/2078.1/176578 |