Modeling of Energy Backscatter via an Algebraic Subgrid Stress Model

2006 ◽  
Author(s):  
Shanti Bhushan ◽  
Zahir Warsi ◽  
Keith Walters
Keyword(s):  
Stress Model ◽  
Subgrid Stress

scholarly journals A physical-space version of the stretched-vortex subgrid-stress model for large-eddy simulation

2000 ◽  
Vol 12 (7) ◽  
pp. 1810-1825 ◽  
Author(s):  
Tobias Voelkl ◽  
D. I. Pullin ◽  
Daniel C. Chan
Keyword(s):  
Large Eddy Simulation ◽  
Physical Space ◽  
Stress Model ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Subgrid Stress

Explicit algebraic subgrid stress models with application to rotating channel flow

2009 ◽  
Vol 639 ◽  
pp. 403-432 ◽  
Author(s):  
LINUS MARSTORP ◽  
GEERT BRETHOUWER ◽  
OLOF GRUNDESTAM ◽  
ARNE V. JOHANSSON
Keyword(s):  
Dynamic Model ◽  
Reynolds Stress ◽  
Channel Flow ◽  
Stress Model ◽  
Smagorinsky Model ◽  
Mean Velocity ◽  
The Mean ◽  
Stress Models ◽  
Subgrid Stress ◽  
Rotating Channel

New explicit subgrid stress models are proposed involving the strain rate and rotation rate tensor, which can account for rotation in a natural way. The new models are based on the same methodology that leads to the explicit algebraic Reynolds stress model formulation for Reynolds-averaged Navier–Stokes simulations. One dynamic model and one non-dynamic model are proposed. The non-dynamic model represents a computationally efficient subgrid scale (SGS) stress model, whereas the dynamic model is the most accurate. The models are validated through large eddy simulations (LESs) of spanwise and streamwise rotating channel flow and are compared with the standard and dynamic Smagorinsky models. The proposed explicit dependence on the system rotation improves the description of the mean velocity profiles and the turbulent kinetic energy at high rotation rates. Comparison with the dynamic Smagorinsky model shows that not using the eddy-viscosity assumption improves the description of both the Reynolds stress anisotropy and the SGS stress anisotropy. LESs of rotating channel flow at Reτ = 950 have been carried out as well. These reveal some significant Reynolds number influences on the turbulence statistics. LESs of non-rotating turbulent channel flow at Reτ = 950 show that the new explicit model especially at coarse resolutions significantly better predicts the mean velocity, wall shear and Reynolds stresses than the dynamic Smagorinsky model, which is probably the result of a better prediction of the anisotropy of the subgrid dissipation.

scholarly journals A vortex-based subgrid stress model for large-eddy simulation

1997 ◽  
Vol 9 (8) ◽  
pp. 2443-2454 ◽  
Author(s):  
Ashish Misra ◽  
D. I. Pullin
Keyword(s):  
Large Eddy Simulation ◽  
Stress Model ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Subgrid Stress

Modeling of Energy Backscatter via an Algebraic Subgrid-Stress Model

AIAA Journal ◽  
2006 ◽  
Vol 44 (4) ◽  
pp. 837-847 ◽  
Author(s):  
S. Bhushan ◽  
Z. U. A. Warsi ◽  
D. K. Walters
Keyword(s):  
Stress Model ◽  
Subgrid Stress

Assesment of Modeling and Discretization Error in Finite-Volume Large Eddy Simulations

2006 ◽  
Author(s):  
Adetokunbo A. Adedoyin ◽  
D. Keith Walters ◽  
Shanti Bhushan
Keyword(s):  
Turbulent Flows ◽  
Finite Volume ◽  
Isotropic Turbulence ◽  
Decay Rates ◽  
Large Eddy Simulations ◽  
Spectral Energy ◽  
Stress Model ◽  
Discretization Scheme ◽  
Large Eddy ◽  
Subgrid Stress

Large eddy simulations of turbulent flows are known to suffer from two separate error sources: the subgrid stress model and the numerical discretization scheme. In general, the two sources of error cannot be separately quantified for finite-difference/finite-volume CFD simulations. The motivation of this paper lies in the desire to determine optimum combinations of currently available subgrid stress models and numerical schemes for use in large eddy simulations of complex flows. Error assessments for large eddy simulation of turbulent fluid flow are presented. These assessments were carried out using pseudospectral simulation techniques in order to isolate finite-differencing and modeling errors by explicitly adding numerical derivative error terms to the simulations and analyzing their effect. Results from several combinations of subgrid stress model and spatial discretization scheme are presented. Simulations were performed for decaying isotropic turbulence on both 323 and 643 grids. Results were compared in terms of spectral energy distributions at succeeding time intervals. For verification, the pseudo-spectral results were compared to LES solutions obtained from a commercially available finite-volume flow solver (FLUENT), and comparisons were made in terms of energy decay rates, numerical versus subgrid stress dissipation levels, and computed energy spectra. The results highlight the interaction between subgrid stress model and discretization scheme. The results also indicate that certain combinations of model and numerical scheme may be more appropriate for finite-volume LES than others.

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