Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7046254 | Applied Thermal Engineering | 2018 | 33 Pages |
Abstract
The thermo-hydraulic performance of coiled-wire inserted in a tube was experimentally investigated. The wire inserts have equilateral triangular cross-sections; they were coiled in a specific way to ensure that a vertex of the triangle was oriented to face the incoming air flow. The coiled-wires were installed with a 1â¯mm separation from the inner tube wall so that the heat transfer enhancement due to the viscous sublayer disturbance could be investigated. In total, six different coiled-wire configurations (three different pitch-to-diameter ratios: P/Dâ¯=â¯1, P/Dâ¯=â¯2 and P/Dâ¯=â¯3 and two different ratios of triangle side-length to tube diameter: e/Dâ¯=â¯0.0714 and e/Dâ¯=â¯0.0892) were chosen for the experiment. To determine the effect of triangle position on thermal performance, the results of present study were compared with a previous study results. The maximum thermal performance is approximately 1.67 times that for a smooth tube was observed for a wire with ratios of e/Dâ¯=â¯0.0892, P/Dâ¯=â¯1 and 11-18% more heat transfer enhancement was achieved than the previous work results. In conclusion, to enhance heat transfer, a coiled-wire that a vertex of the triangle is oriented to face the flow can be widely applied wherever heat exchangers with tubes are used.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Fluid Flow and Transfer Processes
Authors
Orhan Keklikcioglu, Veysel Ozceyhan,