Comparison of the Sigma and Smagorinsky LES models for grid generated turbulence and a channel flow

Rieth, Martin; Proch, Fabian; Stein, Oliver T.; Pettit, M.W.A.; Kempf, Andreas

doi:10.1016/j.compfluid.2014.04.018

Cited by 55 publications

(31 citation statements)

References 24 publications

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“…O modelo de turbulência utilizado é um modelo de simulação de grandes turbilhões (LES) (do inglês Large Eddy Sumulation), de uma equação de turbulência, tal qual o modelo proposto por Smagorinsky (Rieth et al, 2014). Porém, o modelo utilizado neste trabalho resolve uma equação de transporte adicional para a energia ciné-tica turbulenta (ECT) para as escalas de sub grade (ESG).…”

Section: Metodologiaunclassified

Ocorrência De Intermitência Na Transição Laminar-Turbulenta Em Um Escoamento De Couette Plano

Schuster

Stüker

et al. 2016

CeN

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Resumo A transição de regime de escoamento laminar-turbulenta é importante na maioria das áreas de aplicação de mecânica de fluidos. Na camada limite planetária (CLP), o escoamento é predominantemente turbulento. Todavia, logo após o ocaso, a incidência de radiação solar cessa e a superfície passa a perder calor através da emissão de ondas longas, dando origem a uma camada limite estavelmente estratificada (CLE), onde a turbulência pode ser suprimida praticamente em todas as suas escalas. Nestas condições

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Section: Metodologiaunclassified

Ocorrência De Intermitência Na Transição Laminar-Turbulenta Em Um Escoamento De Couette Plano

Schuster

Stüker

et al. 2016

CeN

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“…Closely spaced jets in an opposed jet burner issuing through turbulence-generating plates have been investigated experimentally by Böhm et al (2010) and computationally using LES by Stein et al (2011) and using both LES and DNS by Rieth et al (2014). In both CFD simulations and experiments three regions were found for the jets in the turbulent opposed burners.…”

Section: 3mentioning

confidence: 99%

Experimental and Numerical Investigations of Confluent Round Jets

Svensson¹

2015

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Unconfined multiple interacting confluent round jets are interesting from a purely scientific point of view, as interaction between neighboring jets brings additional complexity to the flow field. Unconfined confluent round jets also exist in various engineering applications, such as ventilation supply devices, sewage disposal systems, combustion burners, chemical mixing or chimney stacks. Even so, little scientific attention has been paid to unconfined confluent round jets, and detailed investigations on the complete three-dimensional turbulent flow field of confluent jet configurations issuing into an unconfined stagnant environment are scarce.The present work uses both advanced measurement techniques and computational models to provide deeper understanding of the turbulent flow field development of unconfined confluent round jets. Both Laser Doppler Anemometry (LDA) and Particle Image Velocimetry (PIV) have been used to measure mean velocity and turbulence properties within two setups, consisting of a single row of 1×6 jets and a square in-line array of 6×6 confluent jets. LDA was used for measurements very close to the nozzle inlets and to verify the main findings made with PIV. A comparison between LDA and PIV results showed that the two measurement techniques produced results that are in good agreement with each other.Simulations using Computational Fluid Dynamics (CFD) of the 6×6 setup were conducted using three different Reynolds Averaged Navier-Stokes (RANS) turbulence models: the standard k-ε, the RNG k-ε and the Reynolds Stress Model (RSM). The results from the CFD simulations were compared with the experimental PIV data. The employed RANS turbulence models were all capable of accurately predicting mean velocities and turbulent properties in the investigated confluent jet array. In general the RSM and the standard k-ε model provided smaller deviations between numerical and experimental results than the RNG k-ε model. In terms of mean velocity the second-order closure model (RSM) was not found to be superior to the less complex standard k-ε model.The validated CFD results provide data at all locations in the solution domain and the computational results were used to further analyze the investigated confluent jet array. The validated CFD model was also employed in a parametrical investigation, including five independent variables: inlet velocity, nozzle diameter, nozzle edge-toedge spacing, nozzle height and the number of jets in the array. The parametrical investigations made use of statistical methods in the form of Response Surface Methodology and Box-Behnken Design of Experiments. The derived response surface models provided information on the principal influence and relative importance of the investigated parameters within the design limits.ii The positions of the jets within the array strongly influence both mean velocity and turbulence. In all investigated setups the jets experience merging and combining. Square arrays also include considerable jet convergence, which was not present in th...

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“…The experimental data and numerical simulations in Böhm et al (2010); Rieth et al (2014); Stein et al (2011) show three regions. An initial region with a constant jet velocity and low velocities between the jets is located near the nozzle plate.…”

Section: Multiple Jetsmentioning

confidence: 99%

Near-Field Study of Multiple Interacting Jets : Confluent Jets

Ghahremanian¹

2015

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Comparison of the Sigma and Smagorinsky LES models for grid generated turbulence and a channel flow

Cited by 55 publications

References 24 publications

Ocorrência De Intermitência Na Transição Laminar-Turbulenta Em Um Escoamento De Couette Plano

Ocorrência De Intermitência Na Transição Laminar-Turbulenta Em Um Escoamento De Couette Plano

Experimental and Numerical Investigations of Confluent Round Jets

Near-Field Study of Multiple Interacting Jets : Confluent Jets

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