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Investigation of turbulent heat transfer in round tubes fitted with regularly spaced overlap dual twisted tape elements |
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| รหัสดีโอไอ | |
| Creator | W. Changcharoen, P. Somravysin, P. Promthaisong, P. Eiamsa-ard, K. Nanan, and S. Eiamsa-ard |
| Title | Investigation of turbulent heat transfer in round tubes fitted with regularly spaced overlap dual twisted tape elements |
| Publisher | Thai Society of Mechanical Engineers |
| Publication Year | 2558 |
| Journal Title | Journal of Research and Applications in Mechanical Engineering |
| Journal Vol. | 3 |
| Journal No. | 2 |
| Page no. | 64-74 |
| Keyword | Dual swirl flows, dual twisted tapes, flow-field, heat transfer enhancement |
| ISSN | 2229-2152 |
| Abstract | A numerical investigation of turbulent forced convection in three-dimensional tubes with twisted tape inserts is performed in order to gain an understanding of physical behavior of the fluid flow (overlap dual swirling flows), fluid temperature and local Nusselt number in the tubes fitted with RS-O-DTs. Effects of the regularly spaced overlap dual twisted tape elements (RS-O-DTs) in counter arrangement on heat transfer and friction factor in circular tubes are reported. Computations, based on a finite volume method, are performed by utilizing the RNG k-? turbulence model. Parametric runs are made for Reynolds numbers between 5000 and 15,000 at various free space ratios (s/W = 2.0, 3.0, and 4.0). From the numerical results reveal that the tube with the RS-O-DTs with the smallest free space ratio (s/W = 2.0), yield higher heat transfer rate by about 180% over the plain tube, and by around 3.1% and 4.0%, over the tubes with RS-O-DTs with s/W = 3.0 and 4.0, respectively. |
