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Fin-and-tube heat exchanger enhancement with a combined herringbone and vortex generator design

Research output: Contribution to journalArticleScientificpeer-review

Details

Original languageEnglish
Pages (from-to)602-616
Number of pages15
JournalInternational Journal of Heat and Mass Transfer
Volume118
Early online date2017
DOIs
Publication statusPublished - 2018
Publication typeA1 Journal article-refereed

Abstract

Vortex generators (VGs) are the most commonly investigated enhancement methods in the field of improved heat exchangers. The aim of present work is to study the effect of VGs in a fin-and-tube heat exchanger (FTHE) with herringbone fin shape. The delta winglet VG design with length (s) and height (H) is selected based on previous studies. The investigated VG design is simple and considered realistic from the manufacturing point of view. The combined enhancement with herringbone fin and the VG is evaluated by simulating the conjugate heat transfer and the air flow. The structured mesh is created for both solid and fluid domains to solve the model numerically using a coupled open source solver in OpenFOAM. The influence of flow condition on the performance enhancement is studied by changing the Reynolds number in a range Re=1354–6157. The study showed that VGs not only increase the heat transfer in the herringbone fin but also decrease the pressure drop. The highest and longest investigated VG design is found to perform the best because of its ability to delay the flow detachment from the tube, to feed high kinetic energy flow to the recirculation zone and to create longitudinal vortices in the downstream region from the VG. The fin with VG design s=0.5D and H=0.6Fp enhances the overall performance by 5.23% in comparison to the fin without VG. The results demonstrated the usefulness of VGs for the performance enhancement in connection with a herringbone fin design.

Keywords

  • Conjugate heat transfer, Fin-and-tube heat exchanger, Herringbone fin, Vortex generator

Publication forum classification

Field of science, Statistics Finland