THERMAL SCIENCE

International Scientific Journal

Zhimin Lin

,

Zhaocheng Wang

,

Sha Li

,

Liangbi Wang

,

Yongheng Zhang

,

Weiwei Wang

,

Jing He

HEAT TRANSFER AUGMENTATION CHARACTERISTICS OF A FIN PUNCHED WITH CURVE TRAPEZOIDAL VORTEX GENERATORS AT THE REAR OF TUBES

ABSTRACT
The thermal-hydraulic characteristics of a novel fin punched with curve trapezoidal vortex generators (CTVG) are investigated numerically. The effects of multi-parameters including the geometry of CTVG, the location of CTVG, and working condition on thermal performance are considered. On one hand, CTVG can availably lessen the size of tube wake zone, decrease the mechanical energy consumption and heighten the fin heat transfer ability in this area. On the other hand, the secondary flow strength is strengthened because the longitudinal vortices generated by CTVG, which efficiently enhances the heat transfer on the fin downstream CTVG. Close relationship exists between the volume-averaged secondary flow strength and the mean Nusselt number. For studied cases, the optimal circumferential location angle of β = 90º is found, while the optimal radial location Dg is about 1.8 times the tube outside diameter. The smaller is the height or base length of CTVG, the better the thermal performance of the enhanced fin punched with CTVG. Better thermal performance is achieved as the fin spacing is about 0.24 times the tube outside diameter.
KEYWORDS
finned tube heat exchanger, heat transfer augmentation, curve trapezoidal vortex generators, numerical simulation
PAPER SUBMITTED: 2021-08-27
PAPER REVISED: 2021-11-12
PAPER ACCEPTED: 2021-11-15
PUBLISHED ONLINE: 2022-01-02
DOI REFERENCE: https://doi.org/10.2298/TSCI210827352L
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2022, VOLUME 26, ISSUE Issue 4, PAGES [3529 - 3544]
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Heat transfer augmentation characteristics of a fin punched with curve trapezoidal vortex generators at the rear of tubes

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