Large eddy simulation of turbulent channel flows by the variational multiscale method

Hughes, Thomas J.R.; Oberai, Assad A.; Mazzei, Luca

doi:10.1063/1.1367868

Cited by 401 publications

(258 citation statements)

References 26 publications

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“…The method has a variational basis, as it relies on "projecting" the subgrid model onto the fine-scale motions, 10 and it was shown to outperform conventional LES models in Hughes et al 9 It appeared that extracting energy only from high wave number modes led to better results than formulations which extract energy from all modes. Subsequent studies have also confirmed the good behavior of the variational multiscale method on a variety of problems: see Hughes, Oberai, and Mazzei, 11 Winckelmans and Jeanmart, 12 Oberai and Hughes, 13 Farhat and Koobus, 14 Jeanmart and Winckelmans, 15 Holmen et al, 16 Koobus and Farhat,17 Ramakrishnan and Collis. [18][19][20][21] In this work, the spectral eddy viscosities for the conventional dynamic Smagorinsky model and the variational multiscale model are calculated and examined for a range of discretizations.…”

Section: Introductionmentioning

confidence: 88%

Energy transfers and spectral eddy viscosity in large-eddy simulations of homogeneous isotropic turbulence: Comparison of dynamic Smagorinsky and multiscale models over a range of discretizations

2004

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Energy transfers within large-eddy simulation (LES) and direct numerical simulation (DNS) grids are studied. The spectral eddy viscosity for conventional dynamic Smagorinsky and variational multiscale LES methods are compared with DNS results. Both models underestimate the DNS results for a very coarse LES, but the dynamic Smagorinsky model is significantly better. For moderately to well-refined LES, the dynamic Smagorinsky model overestimates the spectral eddy viscosity at low wave numbers. The multiscale model is in good agreement with DNS for these cases. The convergence of the multiscale model to the DNS with grid refinement is more rapid than for the dynamic Smagorinsky model.

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Section: Introductionmentioning

confidence: 88%

Energy transfers and spectral eddy viscosity in large-eddy simulations of homogeneous isotropic turbulence: Comparison of dynamic Smagorinsky and multiscale models over a range of discretizations

2004

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“…[3][4][5] For single-phase flows, large-eddy simulation ͑LES͒ has gradually become a more and more powerful tool, which produces acceptable results with much less computational effort compared to DNS. The development of more accurate subgrid modeling strategies, such as dynamic modeling, 6 approximate deconvolution models, 7 the variational multiscale model, 8,9 and the regularization principle, 10 have demonstrated the large potential of LES for various single-phase turbulent flows.…”

Section: Introductionmentioning

confidence: 99%

Subgrid modeling in particle-laden channel flow

2006

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Direct numerical simulation ͑DNS͒ and large-eddy simulation ͑LES͒ of particle-laden turbulent channel flow, in which the particles experience a drag force, are investigated for two subgrid models and several Reynolds and Stokes numbers. In this flow, turbophoresis leads to an accumulation of particles near the walls. The objectives of the work are to investigate the accuracy of the subgrid models studied with respect to particle behavior and to explain the observed particle behavior predicted by the different models. The focus is on particle dispersion and mean particle motion in the direction normal to the walls of the channel. For a low Reynolds number, it is shown that the turbophoresis and particle velocity fluctuations are reduced compared to DNS, if the filtered fluid velocity calculated in the LES is used in the particle equation of motion. This is a combined effect of the disregard of the subgrid scales in the fluid velocity and the inadequacy of the subgrid model. Better agreement with DNS is obtained if an inverse filtering model, which was recently proposed, is incorporated into the particle equation. This model is shown to enhance turbophoresis and particle velocity fluctuations in actual LES. The results of the approximate deconvolution model ͑ADM͒ agree better with DNS results than results of the dynamic eddy-viscosity model. This can be explained from the better prediction of the fluid velocity statistics by ADM and the better correspondence of the subgrid models adopted in the fluid and particle equations. Although the differences between the two subgrid models become smaller, similar conclusions are obtained at a higher Reynolds number. Compared to fourth-order interpolation of the fluid velocity to the particle position, second-order interpolation approximately cancels the effect of the subgrid model in the particle equation of motion.

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“…[15,16]). Recently, VMS Smagorinsky models have become very popular [9,11,12,13,14,17]. In the current work, we employ the small-small variant of the VMS Smagorinksy model in a slightly modified form (ensuring correct low-Re asymptotic behavior) [18,13], i.e.…”

Section: Governing Equationsmentioning

confidence: 99%

“…One class of models, which have become popular recently, are the variational multi-scale (VMS) Smagorinsky models first introduced by Hughes et al [9,10]. These models explicitly employ high-pass filters, which restrict the models effect to small resolved scales, where turbulent energy needs to be removed from the flow.…”

Section: Introductionmentioning

confidence: 99%

“…These models explicitly employ high-pass filters, which restrict the models effect to small resolved scales, where turbulent energy needs to be removed from the flow. In recent years, development and testing of VMS models often relied on simple test cases such as channel flows with two homogeneous directions parallel to the walls, and filtering was only performed along wall-parallel directions [9,11,12,13,14]. For general applicability, the SGS model and associated high-pass filter should be fully three-dimensional in space.…”

Section: Introductionmentioning

confidence: 99%

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Globally conservative high-order filters for large-eddy simulation and computational aero-acoustics

Wu¹,

Meyers²

2011

Computers & Fluids

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In computational aero-acoustics, large-eddy simulations (LES) or direct numerical simulations (DNS) are often employed for flow computations in the source region. As part of the numerical implementation or required modeling, explicit spatial filters are frequently employed. For instance, in LES spatial filters are employed in the formulation of various subgrid-scale (SGS) models such as the dynamic model or the variational multi-scale (VMS) Smagorinsky model; both in LES or DNS, spatial high-pass filters are often used to remove undesired grid-to-grid oscillations.Though these type of spatial filters adhere to local accuracy requirements, in practice, they often destroy global conservation properties in the presence of non-periodic boundaries conditions. This leads to the incorrect prediction of the flow properties near the hard boundaries, such as walls. In the current work, we present globally conservative high-order accurate filters, which combine traditional filters at the internal points with one-sided conservative filters near the wall boundary. We test these filters to remove grid-to-grid oscillations both in a channel-flow case and in 2D cavity flow. We find that the use of a non-conservative filter leads to erroneous predictions of the skin friction in channel flows up to 30%. In the cavity-flow simulations, the use of non-conservative filters to remove grid-to-grid oscillations leads to important shifts in the Strouhal number of the dominant mode, and a change of the flow pattern inside the cavity. In all cases, the use of conservative high-order filter formulations to remove grid-to-grid oscillations lead to very satisfactory results. Finally, in our channel-flow test case, we also illustrate the importance of using conservative filters for the formulation of the VMS Smagorinsky model.

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Large eddy simulation of turbulent channel flows by the variational multiscale method

Cited by 401 publications

References 26 publications

Energy transfers and spectral eddy viscosity in large-eddy simulations of homogeneous isotropic turbulence: Comparison of dynamic Smagorinsky and multiscale models over a range of discretizations

Energy transfers and spectral eddy viscosity in large-eddy simulations of homogeneous isotropic turbulence: Comparison of dynamic Smagorinsky and multiscale models over a range of discretizations

Subgrid modeling in particle-laden channel flow

Globally conservative high-order filters for large-eddy simulation and computational aero-acoustics

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