Comparison of near-wall treatment methods for high Reynolds number backward-facing step flow

Kim, Jae Yong; Ghajar, Afshin J.; Tang, Clement C.; Foutch, Gary L.

doi:10.1080/10618560500502519

Cited by 48 publications

(20 citation statements)

References 4 publications

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“…The above points have been concluded in studies that consider flow properties [28,29,31]. However, heat transfer prediction is quite sensitive to the near-wall modeling in impinging heat transfer, especially for the stagnation region [23], and the y þ requirement cannot be satisfied for the stagnation zone even if improved wall treatment methods are used [14].…”

Section: Introductionmentioning

confidence: 88%

“…A comparison of near-wall treatment methods for high-Reynolds-number backward-facing step flow was performed by Kim et al [28], and a similar study for zero-pressure gradient and obstacle flow was conducted by Salim and Cheah [29] with the FLUENT CFD package. The danger of overrefining the cells adjacent to the walls has been emphasized by Chila and Kaminski [30,31], and they have proposed a novel approach toward using an automated adaptation procedure for obtaining grid independence.…”

Section: Introductionmentioning

confidence: 99%

“…A proper combination of near-wall treatment methods and turbulence models should be used [28,29]. 2.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effect of Turbulence Models and Near-Wall Modeling Approaches on Numerical Results in Impingement Heat Transfer

Pulat

Isman

Etemoğlu

et al. 2011

Numerical Heat Transfer, Part B: Fundamentals

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In this study, turbulence models and near-wall modeling approaches were compared in impingement heat transfer. The Reynolds-averaged Navier-Stokes (RANS) turbulence models were compared using three near-wall modeling approaches. Moreover, the effect of near-wall modeling approaches on heat transfer was investigated and the predictions were compared with experiments. All computations were performed with the FLUENT code by considering two-dimensional, steady, and incompressible flow. Wall functions (WF) should be used carefully in conjunction with turbulence models, and the enhanced wall treatment (WT) is suggested for practical applications. The standard k-e model showed the best agreement with the experimental data among the models used under the considered conditions.

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Section: Introductionmentioning

confidence: 88%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of Turbulence Models and Near-Wall Modeling Approaches on Numerical Results in Impingement Heat Transfer

Pulat

Isman

Etemoğlu

et al. 2011

Numerical Heat Transfer, Part B: Fundamentals

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“…Ye J et al [2] established the k-ε-s model based on random turbulence theory and increased the precision of vortex length calculation. The studies of You X Y et al [3] and Kim J Y et al [4] compared and studied those models with various improvements. The computed recirculation length increased, but calculated pressure coefficient was still different from the tested data by about 20% when comparing the RKE & RNG model and the standard k-ε turbulence model (SKE).…”

Section: Introductionmentioning

confidence: 99%

Numerical application of k-ɛ turbulence model to the flow over a backward-facing step

Ding

2010

Sci. China Technol. Sci.

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A model that uses the operator splitting technique based on Eulerian-Lagrangian method and embeds the k-ε turbulence mode is developed. The model is used to simulate a two dimensional flow over a backward-facing step with triangular mesh discrete flow field. The convection operator is solved with the characteristic method and the diffusion operator and pressure-Poisson equation are solved by finite element method. The results from the example showed that numerical results are well agreed with the experimental data, and that the method can be adapted to simulate complex turbulent flow with strong non-linear convection. The treatment of boundary conditions is also studied in the paper. turbulence model, the flow over a backward-facing step, numerical method Citation:Ding D Y, Wu S Q. Numerical application of k-ε turbulence model to the flow over a backward-facing step.

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“…Therefore, special treatment is required to solve for the wall-bounded flow field; a solution that also depends on the choice of RANS model that solves for the main flow field. Reliable results can be achieved via proper selection of both RANS and near-wall models (Kim et al 2005). Temperature profile in this region must be determined correctly for correct heat transfer calculation.…”

Section: Wall Treatmentmentioning

confidence: 99%

Radiation properties of coil-coated steel in building envelope surfaces and the influence on building thermal performance

Joudi¹

2015

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Recent studies have shown that the optical properties of building exterior surfaces are important in terms of energy use and thermal comfort. While the majority of the studies are related to exterior surfaces, the radiation properties of interior surfaces are less thoroughly investigated. Development in the coil-coating industries has now made it possible to allocate different optical properties for both exterior and interior surfaces of steel-clad buildings. The aim of this thesis is to investigate the influence of surface radiation properties with the focus on the thermal emittance of the interior surfaces, the modeling approaches and their consequences in the context of the building energy performance and indoor thermal environment.The study consists of both numerical and experimental investigations. The experimental investigations include parallel field measurements on three similar test cabins with different interior and exterior surface radiation properties in Borlänge, Sweden, and two ice rink arenas with normal and low emissive ceiling in Luleå, Sweden. The numerical methods include comparative simulations by the use of dynamic heat flux models, Building Energy Simulation (BES), Computational Fluid Dynamics (CFD) and a coupled model for BES and CFD. Several parametric studies and thermal performance analyses were carried out in combination with the different numerical methods.The parallel field measurements on the test cabins include the air, surface and radiation temperatures and energy use during passive and active (heating and cooling) measurements. Both measurement and comparative simulation results indicate an improvement in the indoor thermal environment when the interior surfaces have low emittance. In the ice rink arenas, surface and radiation temperature measurements indicate a considerable reduction in the ceiling-to-ice radiation by the use of low emittance surfaces, in agreement with a ceiling-to-ice radiation model using schematic dynamic heat flux calculations.The measurements in the test cabins indicate that the use of low emittance surfaces can increase the vertical indoor air temperature gradients depending on the time of day and outdoor conditions. This is ii in agreement with the transient CFD simulations having the boundary condition assigned on the exterior surfaces. The sensitivity analyses have been performed under different outdoor conditions and surface thermal radiation properties. The spatially resolved simulations indicate an increase in the air and surface temperature gradients by the use of low emittance coatings. This can allow for lower air temperature at the occupied zone during the summer.The combined effect of interior and exterior reflective coatings in terms of energy use has been investigated by the use of building energy simulation for different climates and internal heat loads. The results indicate possible energy savings by the smart choice of optical properties on interior and exterior surfaces of the building.Overall, it is concluded that the interior re...

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Comparison of near-wall treatment methods for high Reynolds number backward-facing step flow

Cited by 48 publications

References 4 publications

Effect of Turbulence Models and Near-Wall Modeling Approaches on Numerical Results in Impingement Heat Transfer

Effect of Turbulence Models and Near-Wall Modeling Approaches on Numerical Results in Impingement Heat Transfer

Numerical application of k-ɛ turbulence model to the flow over a backward-facing step

Radiation properties of coil-coated steel in building envelope surfaces and the influence on building thermal performance

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