The Computation of Flow and Heat Transfer through an Orthogonally Rotating Square-Ended U-Bend Using Low-Reynolds-Number Models
We present computations of heat and fluid flow through a square-ended U-bend that rotates about an axis normal to both the main flow direction and also the axis of curvature. Two-layer and low-Reynolds-number mathematical models of turbulence are used at effective-viscosity (EVM) level and also at s...
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| Format: | Article |
| Language: | English |
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Wiley
2005-01-01
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| Series: | International Journal of Rotating Machinery |
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| Online Access: | http://dx.doi.org/10.1155/IJRM.2005.232 |
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| author | Konstantinos-Stephen P. Nikas Hector Iacovides |
| author_facet | Konstantinos-Stephen P. Nikas Hector Iacovides |
| author_sort | Konstantinos-Stephen P. Nikas |
| collection | DOAJ |
| description | We present computations of heat and fluid flow through a square-ended U-bend that rotates about an axis normal to both the main flow direction and also the axis of curvature. Two-layer and low-Reynolds-number mathematical models of turbulence are used at effective-viscosity (EVM) level and also at second-moment-closure
(DSM) level. Moreover, two length-scale correction terms to the dissipation rate of turbulence are used with the low-Re models, the original Yap term, and a differential form that does not require the wall distance (NYap). The resulting predictions are compared with available flow and heat transfer measurements of water. While the main flow features are well reproduced by all models, the development of the mean flow within and just after the
bend is better reproduced by the low-Re models. Turbulence levels within the rotating U-bend are underpredicted, but DSM models produce a more realistic distribution. Along the leading side, all models overpredict heat transfer levels just after the bend. Along the trailing side, the heat transfer predictions of the low-Re DSM with the NYap, are close to the measurements. |
| format | Article |
| id | doaj-art-589ee9f0eb534dc282550416a611d200 |
| institution | Kabale University |
| issn | 1023-621X 1542-3034 |
| language | English |
| publishDate | 2005-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | International Journal of Rotating Machinery |
| spelling | doaj-art-589ee9f0eb534dc282550416a611d2002025-02-03T05:58:40ZengWileyInternational Journal of Rotating Machinery1023-621X1542-30342005-01-012005323224310.1155/IJRM.2005.232The Computation of Flow and Heat Transfer through an Orthogonally Rotating Square-Ended U-Bend Using Low-Reynolds-Number ModelsKonstantinos-Stephen P. Nikas0Hector Iacovides1Laboratory of Aerodynamics, Department of Mechanical Engineering, National Technical University of Athens (NTUA), 9 Heroon Polytexneiou Street, P.O. Box 64070, Zografou Campus, Athens 15773, GreeceSchool of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Sackville Street, P.O. Box 88, Manchester M60 1QD, UKWe present computations of heat and fluid flow through a square-ended U-bend that rotates about an axis normal to both the main flow direction and also the axis of curvature. Two-layer and low-Reynolds-number mathematical models of turbulence are used at effective-viscosity (EVM) level and also at second-moment-closure (DSM) level. Moreover, two length-scale correction terms to the dissipation rate of turbulence are used with the low-Re models, the original Yap term, and a differential form that does not require the wall distance (NYap). The resulting predictions are compared with available flow and heat transfer measurements of water. While the main flow features are well reproduced by all models, the development of the mean flow within and just after the bend is better reproduced by the low-Re models. Turbulence levels within the rotating U-bend are underpredicted, but DSM models produce a more realistic distribution. Along the leading side, all models overpredict heat transfer levels just after the bend. Along the trailing side, the heat transfer predictions of the low-Re DSM with the NYap, are close to the measurements.http://dx.doi.org/10.1155/IJRM.2005.232RANSlow-Re modelstwo-layer models heat transferstrong curvatureorthogonal rotation. |
| spellingShingle | Konstantinos-Stephen P. Nikas Hector Iacovides The Computation of Flow and Heat Transfer through an Orthogonally Rotating Square-Ended U-Bend Using Low-Reynolds-Number Models International Journal of Rotating Machinery RANS low-Re models two-layer models heat transfer strong curvature orthogonal rotation. |
| title | The Computation of Flow and Heat Transfer through an Orthogonally
Rotating Square-Ended U-Bend Using Low-Reynolds-Number Models |
| title_full | The Computation of Flow and Heat Transfer through an Orthogonally
Rotating Square-Ended U-Bend Using Low-Reynolds-Number Models |
| title_fullStr | The Computation of Flow and Heat Transfer through an Orthogonally
Rotating Square-Ended U-Bend Using Low-Reynolds-Number Models |
| title_full_unstemmed | The Computation of Flow and Heat Transfer through an Orthogonally
Rotating Square-Ended U-Bend Using Low-Reynolds-Number Models |
| title_short | The Computation of Flow and Heat Transfer through an Orthogonally
Rotating Square-Ended U-Bend Using Low-Reynolds-Number Models |
| title_sort | computation of flow and heat transfer through an orthogonally rotating square ended u bend using low reynolds number models |
| topic | RANS low-Re models two-layer models heat transfer strong curvature orthogonal rotation. |
| url | http://dx.doi.org/10.1155/IJRM.2005.232 |
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