Numerical investigation of flow and heat transfer performances of horizontal spiral-coil pipes
| Autor: | Wen-bo Bi, Jia-dong Ji, Ge Peiqi |
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| Rok vydání: | 2016 |
| Předmět: |
Plug flow
Materials science 020209 energy Mechanical Engineering Thermodynamics 02 engineering and technology Mechanics Radius Heat transfer coefficient Condensed Matter Physics Nusselt number Churchill–Bernstein equation Open-channel flow Physics::Fluid Dynamics Mechanics of Materials Modeling and Simulation Heat transfer 0202 electrical engineering electronic engineering information engineering Intensity (heat transfer) |
| Zdroj: | Journal of Hydrodynamics. 28:576-584 |
| ISSN: | 1878-0342 1001-6058 |
| DOI: | 10.1016/s1001-6058(16)60661-3 |
| Popis: | The flow and heat transfer performances of horizontal spiral-coil pipes of circular and elliptical cross-sections are studied. The numerical results are compared with the experimental data, to verify the numerical method. The effects of the inlet water mass flow rate, the structural parameters, the helical pitch and the radius ratio on the heat transfer performances are investigated. Performances of the secondary fluid flow with different radius ratios are also investigated. Numerical results demonstrate that the heat transfer coefficient and the Nusselt number increase with the increase of the water mass flow rate or the helical pitch. The maximum heat transfer coefficient and the maximum Nusselt number are obtained when the radius ratio is equal to 1.00. In addition, the fluid particle moves spirally along the pipe and the velocity changes periodically. The particle flow intensity and the spiral movement frequency decrease significantly with the increase of the radius ratio. Besides, the secondary flow profile in the horizontal spiral-coil pipe contains two oppositely rotating eddies, and the eddy intensity decreases significantly along the pipe owing to the change of curvature. The decreasing tendency of the eddy intensity along the pipe increases with the increase of the radius ratio. |
| Databáze: | OpenAIRE |
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