Доступ предоставлен для: Guest

ISSN Online: 2379-1748

ISBN Flash Drive: 978-1-56700-469-4

ISBN Online: 978-1-56700-470-0

Second Thermal and Fluids Engineering Conference
April, 2-5, 2017, Las Vegas, NV, USA

HEAT TRANSFER AND PRESSURE DROP MECHANISMS IN WAVY FINS HAVING ONE, TWO, THREE AND FOUR ROWS OF TUBES

Get access (open in a dialog) pages 2395-2407
DOI: 10.1615/TFEC2017.iac.017425

Аннотация

Wavy fins are one of the most popular fins in compact heat exchanger used in refrigeration industry. The mechanism responsible for heat transfer and pressure drop in a wavy fin is quite different when compared to plate fin. Wave angle, fin pitch, fin thickness, waffle size, row tubes number and pitches are parameters which decide the performance of the heat exchanger surface. Minimal modifications of these parameters could produce significant improvement of fin's performance. A complete understanding of both heat transfer and pressure drop mechanisms in wavy fin is very important for heat exchanger designers. This work deals with the determination of thermo-hydraulic performance of wavy fin having one, two, three or four rows of tubes. Reynolds number, based in the hydraulic diameter of the channel of the heat exchanger, was always inside the laminar regime, ranging from 200 to 2000. Heat transfer and pressure drop mechanisms were identified. The approach was numerical using Computational Fluid Dynamics. A conjugate heat transfer calculation with coupling walls and periodic conditions was implemented. The impingement flow on surfaces, boundary layer development and horseshoe vortex in front of tube were the identified heat transfer mechanism, with the first one playing a major role. Among the models studied, the model having one row has the large flux heat. Was identified the bottom side of the fin having better performance than top side. The heat transferred by each tube was investigated and the second row of tubes was found as the most effective when compared to the rest ones.