Thermal characteristics in a heat exchanger tube fitted with zigzag‐winglet perforated‐tapes

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S. Suwannapan
S. Skullong
P. Promvonge

Abstract

The paper presents an experimental investigation on enhanced heat transfer and pressure loss characteristics using zigzag-winglet perforated-tape inserts (ZW-PT) in a round tube having a uniform heat-fluxed wall for the turbulent air flow, Reynolds number (Re) from 4200 to 26,000. In the present work, the ZWPT having the winglet attack angle of 45° were inserted into the test tube at two different winglet pitch ratios (P/D = PR=1 and 1.5) and four winglet-width or blockage ratios (b/D = BR=0.1, 0.15, 0.2 and 0.25). The experimental results of the heat transfer and pressure drop in terms of the respective Nusselt number (Nu) and friction factor (f), respectively, reveal that the Nu and f increase with the increment of BR and Re but with the decreasing PR. The Nu for the inserted tube is in a range of 3.1-5.1 times above that for the plain tube while the f is around 12.5-53.6 times. In addition, the use of the ZW-PT with PR=1.0 leads to better thermal enhancement factor (TEF) than that with PR=1.5 around 3-5%.

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How to Cite
Suwannapan, S., Skullong, S., & Promvonge, P. (2018). Thermal characteristics in a heat exchanger tube fitted with zigzag‐winglet perforated‐tapes. Journal of Research and Applications in Mechanical Engineering, 3(1), 29–36. Retrieved from https://ph01.tci-thaijo.org/index.php/jrame/article/view/141535
Section
RESEARCH ARTICLES

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