標題: Compound Heat Transfer Enhancement of Wavy Fin-and-Tube Heat Exchangers through Boundary Layer Restarting and Swirled Flow
作者: Sadeghianjahromi, Ali
Kheradmand, Saeid
Nemati, Hossain
Liaw, Jane-Sunn
Wang, Chi-Chuan
機械工程學系
Department of Mechanical Engineering
關鍵字: wavy fin-and-tube heat exchanger;louver fin;vortex generators;numerical simulation;heat transfer enhancement
公開日期: 1-Aug-2018
摘要: This study performs a 3D turbulent flow numerical simulation to improve heat transfer characteristics of wavy fin-and-tube heat exchangers. A compound design encompassing louver, flat, and vortex generator onto wavy fins can significantly enhance the heat transfer performance of wavy fin-and-tube heat exchangers. Replacement of wavy fins around tubes with flat fins is not effective as far as the reduction of thermal resistance is concerned, although an appreciable pressure drop reduction can be achieved. Adding two louvers with a width of 8 mm to the flat portion can reduce thermal resistance up to 6% in comparison with the reference wavy fin. Increasing the louver number and width can further decrease the thermal resistance. Also, it is found that the optimum louver angle is equal to the wavy angle for offering the lowest thermal resistance. Therefore, compound geometry with three louvers, a width of 12 mm, and the louver angle being equal to wavy angle with waffle height to be the same as fin pitch of the reference wavy fin has the most reduction in thermal resistance of 16% for a pumping power of 0.001 W. Adding punching longitudinal vortex generators on this compound geometry can further decrease thermal resistance up to 18%.
URI: http://dx.doi.org/10.3390/en11081959
http://hdl.handle.net/11536/148260
ISSN: 1996-1073
DOI: 10.3390/en11081959
期刊: ENERGIES
Volume: 11
Appears in Collections:Articles


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