Large-Eddy Simulation of the Flow Over a Circular Cylinder at Reynolds Number 3900 Using the OpenFOAM Toolbox

Lysenko, D. A.; Ertesvåg, Ivar S.; Rian, Kjell Erik

doi:10.1007/s10494-012-9405-0

Cited by 169 publications

(118 citation statements)

References 35 publications

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“…Details of validation and verification of non-reactive RAS and LES were provided previously [31], [32], [33] and are not discussed here. Effects of the SGS models on the LES of the inert flow are briefly discussed in Appendix B.…”

Section: Sas Non-reacting Flow Resultsmentioning

confidence: 99%

“…The reason for not adding perturbations at the inlet for SAS and LES calculations was the same as discussed earlier [32]: In the designed grid, the inflow perturbations will be highly damped due to grid expansion from the surface of the bluff-body towards the inlet boundary, and the probability that these perturbations will reach the triangular cylinder is small.…”

Section: Boundary Conditionsmentioning

confidence: 99%

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Reynolds-Averaged, Scale-Adaptive and Large-Eddy Simulations of Premixed Bluff-Body Combustion Using the Eddy Dissipation Concept

Lysenko¹,

Ertesvåg

2017

Flow Turbulence Combust

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A lean premixed propane/air bluff-body stabilized flame (Volvo test rig) is calculated using the Scale-Adaptive Simulation turbulence model (SAS) and Large-Eddy simulations (LES) as well as the conventional Reynoldsaveraged approach (RAS). RAS and SAS are closed by the standard k-ǫ and the k-ω Shear Stress Transport (SST) turbulence models, respectively. The conventional Smagorinsky and the k-equation sub-grid scales models are used for the LES closure. Effects of the sub-grid scalar flux modeling using the classical gradient hypothesis and Clark's tensor diffusivity closures both for the inert and reactive LES flows are discussed. The Eddy Dissipation Concept (EDC) is used for the turbulence-chemistry interaction. It assumes that molecular mixing and the subsequent combustion occur in the 'fine structures' (smaller dissipative eddies, which are close to the Kolmogorov scales). Assuming the full turbulence energy cascade, the characteristic length and velocity scales of the 'fine structures' are evaluated using different turbulence models (RAS, SAS and LES). The finite-rate chemical kinetics is taken into account by treating the 'fine structures' as constant pressure and adiabatic homogeneous reactors, calculated as a system of ordinary-differential equations (ODEs) described by a Perfectly Stirred Reactor (PSR) concept. Several further enhancements to model the PSRs are proposed, including a new Livermore Solver (LSODA) for integrating stiff ODEs and a new correction to calculate the PSR time scales. All models have been implemented as a stand-alone application edcPisoFoam based on the OpenFOAM technology. Additionally, several RAS calculations were performed using the Turbulence Flame Speed Closure model in Ansys Fluent to assess effects of the heat losses by modeling the conjugate heat transfer between the bluff-body and the reactive flow. Effects of the turbulence Schmidt number on RAS results are discussed as well. Numerical results are compared with available experimental data. Reasonable consistency between experimental data and numerical results provided by RAS, SAS and LES is observed. In general, there is satisfactory agreement between present LES-EDC simulations, numerical results by other authors and measurements without any major modification to the EDC closure constants, which gives a quite reasonable indication on the adequacy and accuracy of the method and its further application for turbulent premixed combustion simulations.

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Section: Sas Non-reacting Flow Resultsmentioning

confidence: 99%

Section: Boundary Conditionsmentioning

confidence: 99%

Reynolds-Averaged, Scale-Adaptive and Large-Eddy Simulations of Premixed Bluff-Body Combustion Using the Eddy Dissipation Concept

Lysenko¹,

Ertesvåg

2017

Flow Turbulence Combust

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“…See [9,28,29] for evaluations of subgrid models implemented into OpenFOAM. In this paper, we compare the simplest (Smagorinsky, denoted S) and most sophisticated (dynamic mixed Smagorinsky, denoted DMS) of these models.…”

Section: Turbulence Modellingmentioning

confidence: 99%

“…There is, for example, a large body of literature concerning Re = 3900 e.g. see [8,9,10,11,12]. Whilst good agreement between numerical and experimental data is typically seen, grid sizes may still be regarded as large (e.g.…”

Section: Introductionmentioning

confidence: 99%

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Large eddy simulations of a circular cylinder at Reynolds numbers surrounding the drag crisis

Lloyd

James

2016

Applied Ocean Research

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Large eddy simulations of the flow around a circular cylinder at high Reynolds numbers are reported. Five Reynolds numbers were chosen, such that the drag crisis was captured. A total of 18 cases were computed to investigate the effect of gridding strategy, domain width, turbulence modelling and numerical schemes on the results. It was found that unstructured grids provide better resolution of key flow features, when a 'reasonable' grid size is to be maintained.When using coarse grids for large eddy simuation, the effect of the turbulence models and numerical schemes becomes more pronounced. The dynamic mixed Smagorinsky model was found to be superior to the Smagorinsky model, since the model coefficient is allowed to dynamically adjust based on the local flow and grid size. A blended upwind-central convection scheme was also found to provide the best accuracy, since a fully central scheme exhibits artificial wiggles which pollute the entire solution.Mean drag, fluctuating lift and Strouhal number are compared to experiments and empirical estimates for Reynolds numbers ranging from 6.31 × 10 4 − 5.06 × 10 5 . In terms of the drag coefficient, the drag crisis is well captured by the present simulations, although the other integral quantities (rms lift and Strouhal number) less so. For the lowest Reynolds number, the drag is seen to be most sensitive to the domain width, while at the higher Reynolds numbers the grid resolution plays a more important role.

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A new model for predicting the drag exerted by vegetation canopies

Farooji

Lowe

Ghisalberti

2017

Water Resources Research

105

130

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The influence of vegetation canopies on the flow structure in streams, rivers, and floodplains is heavily dependent on the cumulative drag forces exerted by the vegetation. The drag coefficients of vegetation elements within a canopy have been shown to be significantly different from the well‐established value for a single element in isolation. This study investigates the mechanisms that determine canopy flow resistance and proposes a new model for predicting canopy drag coefficients. Large Eddy Simulations were used to investigate the fine‐scale hydrodynamics within emergent canopies with solid area fractions ( λ) ranging from 0.016 to 0.25. The influences of three mechanisms in modifying canopy drag, namely, blockage, sheltering, and delayed separation, were investigated. While the effects of sheltering and delayed separation were found to slightly reduce the drag of very sparse canopies, the blockage effect significantly increased the drag of denser canopies ( λ≳0.04). An analogy between canopy flow and wall‐confined flow around bluff bodies is used to identify an alternative reference velocity in the definition of the canopy drag coefficient; namely, the constricted cross‐section velocity (Uc). Through comparison with both prior experimental data and the present numerical simulations, typical formulations for the drag coefficient of a single cylinder are shown to accurately predict the drag coefficient of staggered emergent canopies when Uc is used as the reference velocity. Finally, it is shown that this new model can be extended to predict the bulk drag coefficient of randomly arranged vegetation canopies.

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Large-Eddy Simulation of the Flow Over a Circular Cylinder at Reynolds Number 3900 Using the OpenFOAM Toolbox

Cited by 169 publications

References 35 publications

Reynolds-Averaged, Scale-Adaptive and Large-Eddy Simulations of Premixed Bluff-Body Combustion Using the Eddy Dissipation Concept

Reynolds-Averaged, Scale-Adaptive and Large-Eddy Simulations of Premixed Bluff-Body Combustion Using the Eddy Dissipation Concept

Large eddy simulations of a circular cylinder at Reynolds numbers surrounding the drag crisis

A new model for predicting the drag exerted by vegetation canopies

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