Computations of flow and heat transfer in a rotating U-shaped square duct with smooth walls

Stephens, Mark; Shih, Tsan‐Hsing; Civinskas, K. C.

doi:10.2514/6.1996-3161

Cited by 21 publications

(15 citation statements)

References 27 publications

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“…Solutions were generated by using a cellcentered finite-volume method on a structured grid based on second-order accurate Roe differencing, and on a diagonalized alternating-direction implicit scheme with local time-stepping and V-cycle multigrid. Details on this test case are provided in [26].…”

Section: B7 Heat Transfer In a Smooth U-duct With And Without Rotationmentioning

confidence: 99%

The AIAA Code Verification Project - Test cases for CFD Code Verification

Ghia¹,

Bayyuk²,

Habchi³

et al. 2010

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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This paper presents a collection of fluid mechanics problems with exact solutions which can be used to verify the numerical accuracy of solutions obtained by CFD codes. This document is a product of the AIAA Committee On Standards (COS). It is intended to serve as the start of a catalog of exact solutions for fluid mechanics problems, and as a complement to the Verification and Validation Guide prepared by the AIAA. While the solutions presented in this paper do not necessarily test all aspects of a code or all terms of the governing equations, they constitute fundamentals tests for identifying coding errors. Hence, documenting these solutions is an important step towards consolidating significant verification cases.

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Section: B7 Heat Transfer In a Smooth U-duct With And Without Rotationmentioning

confidence: 99%

The AIAA Code Verification Project - Test cases for CFD Code Verification

Ghia¹,

Bayyuk²,

Habchi³

et al. 2010

48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

Self Cite

View full text Add to dashboard Cite

show abstract

“…18 used standard logarithmic wall function in a commercial code. For a lower-Reynolds-number case, Re = 2.5 × 10 4 , Stephens et al 10 were able to use a large Reynolds number (LRN) k−ω turbulence model on a 1.1 × 10 6 mesh for their compressible simulation. The result was in good agreement with the measured data.…”

Section: Combined Effects Of Rotation Number and Densitymentioning

confidence: 99%

“…Applying a modified k−ε model, Dutta et al 9 showed satisfactory predictions on the radial outward flow. Stephens et al 10 used a k−ω model to simulate the smooth square duct with U turn. The k−ω model showed good heattransfer results agreement with those measured by Wagner et al, 1 except at the leading surface of the first pass where an overestimation was predicted.…”

Section: Channels-numerical Simulationsmentioning

confidence: 99%

Effect of Coriolis and Centrifugal Forces at High Rotation and Density Ratios

Sleiti

Kapat

2006

Journal of Thermophysics and Heat Transfer

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Numerical simulation of fluid flow and heat transfer of high rotation and density ratio flow in internal cooling channels of turbine blades with smooth walls is the main focus of this study. The flow in these channels is affected by rotation, buoyancy, bends, and boundary conditions. On the basis of comparison between two-equation (k− −ε and k− −ω) and Reynolds-stress (RSM) turbulence models, it is concluded that the two-equation turbulence models cannot predict heat transfer correctly, whereas RSM showed improved prediction. Thus RSM model was validated against available experimental data (which are primarily at low rotation and buoyancy numbers). The model was then used for cases with high rotation numbers (as much as 1.29) and high-density ratios (up to 0.4) not studied previously. Particular attention was given to how Reynolds stresses, turbulence intensity, and transport are affected by coriolis and buoyancy/centrifugal forces caused by high levels of rotation and density ratio. The results obtained are explained in view of physical interpretation of Coriolis and centrifugal forces. It has been concluded that the heat-transfer rate can be enhanced rapidly by increasing rotation number to values that are comparable to the enhancement caused by introduction of ribs inside internal cooling channels. It is possible to derive linear correlation for the increase in Nusselt number as a function of rotation number. Increasing density ratios at high rotation number does not necessarily cause an increase in Nusselt number. The increasing thermal boundary-layer thickness near walls is the possible reason for this behavior ofNusselt number. Nomenclature a ce = acceleration caused by centrifugal force a co = acceleration caused by Coriolis force D h = hydraulic diameter f ce = centrifugal force f co = Coriolis force N u = local Nusselt number, h D h /k N u 0 = Nusselt number in fully developed turbulent nonrotating tube flow Pr = Prandtl number Pr t = turbulent Prandtl number R = radius from axis of rotation Re = Reynolds number, ρW 0 D h /µ Ro = rotation number, D h /W 0 r = inner radius of bend S = distance in streamwise direction T = local coolant temperature T b = coolant bulk temperature T 0= coolant temperature at inlet T w = wall temperature W 0 = inlet velocity ρ/ρ = density ratio, (T w − T 0 )/T w θ = dimensionless temperature, (T − T 0 )/(T w − T 0 ) µ = dynamic viscosity of coolant ρ = density of air

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“…In recent years, some researchers began to use other turbulence models for numerical simulation. Stephens [6] predicted the U-shape channel with the standard k model. Their computational results of heat transfer in the first passage agreed well with the experimental data of Wagner [7].…”

Section: Thermal Conductivity W/(m·k) Numentioning

confidence: 99%

Computational research on rotating channel by a modified anisotropic turbulence model

2011

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Based on the simplified format of the Reynolds stress equations, a fire-new rotational-modification method for the anisotropic turbulence model has been presented. A three-dimensional Navier-Stokes code with this new rotational modified k turbulence models (=0.1 and =1) and the standard k turbulence model have been used for the prediction of flow and heat transfer characteristics in a rotating smooth square channel. The Reynolds number Re based on the inlet velocity of the cooling air and hydraulic diameter is 6000 .The rotating speed are 300, 600, 900, 1200rpm respectively. The calculations results of using three turbulence models have been compared with the experimental data. The research results show that (1) the rotational modification coefficient Rf 13 used in the new anisotropic k model would increased/decreased the predictions of heat transfer on the trailing surface/leading surface compared to the standard k model. And this tendency would be increased with the increased .(2) The simulation performance of the standard k model was well on the leading surface.However, on the trailing surface it under-predicted the heat transfer at high rotating speed. (3) The calculation results of the new anisotropic k model with =0.1 proposed by the present paper agreed well with experimental data, both on the leading and trailing surfaces. Besides, compared to 1, 0.1 is a more appropriate magnitude of  at conditions in the present paper.

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Computations of flow and heat transfer in a rotating U-shaped square duct with smooth walls

Cited by 21 publications

References 27 publications

The AIAA Code Verification Project - Test cases for CFD Code Verification

The AIAA Code Verification Project - Test cases for CFD Code Verification

Effect of Coriolis and Centrifugal Forces at High Rotation and Density Ratios

Computational research on rotating channel by a modified anisotropic turbulence model

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