Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8076995 | Energy | 2014 | 25 Pages |
Abstract
3D computational analysis was performed to investigate heat transfer and pressure drop characteristics of flow in SWFET (Smooth Wavy Fin-and-Elliptical Tube) heat exchanger with four new VGs (vortex generators), RTW (rectangular trapezoidal winglet), ARW (angle rectangular winglet), CARW (curved angle rectangular winglet) and WW (Wheeler wishbone). The numerical model was well validated with the available experimental results. Numerical results illustrate that vortex generators can bring about further heat transfer enhancement through careful adjustment of the position with respect to the elliptical tube, type and attack angle of vortex generators. The influences of the geometrical factors including attack angles of the winglets (αVG = 15â,30â,45â,60â and 75°) and width/length aspect ratio (w/l = 0.5,1.0) of the Wheeler wishbones on enhancing the heat transfer performance of a smooth wavy fin heat exchanger with a three-row staggered elliptical tube bundle are investigated. A parametric study on the winglet vortex generators indicated that for the small attack angle, CARW vortex generators gives better thermohydraulic performance under the present conditions. The best thermal performance with winglet VGs in larger attack angle, was obtained at RTW VGs arrangement. For the SWFET heat exchangers, the WW VGs with w/l = 0.5 provide the best heat transfer performance.
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Physical Sciences and Engineering
Energy
Energy (General)
Authors
Babak Lotfi, Min Zeng, Bengt Sundén, Qiuwang Wang,