Analysis of enhanced turbulent heat transfer in a sharp turn channel having novel designed endwall with longitudinal vortex generator
(2022) In International Communications in Heat and Mass Transfer 131.- Abstract
This work provides a new method to enhance endwall heat transfer of a sharp turn channel. Several longitudinal vortex generators (LVGs) at various spacing and aspect ratio are placed in parallel on the inner side of endwall in a sharp turn channel. Liquid crystal thermography, pressure difference measurements, and a statistical method are applied to analyze the thermal behavior, friction factor, and temperature uniformity on the endwall mounted with an array of LVGs. The Reynolds number are in the range of 10,000 to 20,000. A comparison between the novel designed endwall and conventional turbulators in the same U bend channel is also conducted. Results indicate that the local Nusselt number is greatly augmented with the application of... (More)
This work provides a new method to enhance endwall heat transfer of a sharp turn channel. Several longitudinal vortex generators (LVGs) at various spacing and aspect ratio are placed in parallel on the inner side of endwall in a sharp turn channel. Liquid crystal thermography, pressure difference measurements, and a statistical method are applied to analyze the thermal behavior, friction factor, and temperature uniformity on the endwall mounted with an array of LVGs. The Reynolds number are in the range of 10,000 to 20,000. A comparison between the novel designed endwall and conventional turbulators in the same U bend channel is also conducted. Results indicate that the local Nusselt number is greatly augmented with the application of LVGs on the endwall, especially at the downstream part of the endwall. The LVGs with an aspect ratio of 2 and a spacing of 20 mm (dense case) provides the optimal thermal characteristics. The optimal design provides augmentation of heat transfer rate and thermal performance factor by up to 35.1% and 25.5%, respectively. The endwall fitted with delta-winglet vortex generators is a promising enhanced heat transfer method compared with the conventional design available for the same U-duct model.
(Less)
- author
- Zhao, Zhiqi ; Luo, Lei ; Zhou, Xun ; Wang, Songtao ; Wang, Zhongqi and Sundén, Bengt LU
- organization
- publishing date
- 2022-02
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- enhanced heat transfer, heat exchanger, internal endwall, longitudinal vortex generator, two-pass turn channel
- in
- International Communications in Heat and Mass Transfer
- volume
- 131
- article number
- 105874
- publisher
- Elsevier
- external identifiers
-
- scopus:85122221885
- ISSN
- 0735-1933
- DOI
- 10.1016/j.icheatmasstransfer.2021.105874
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2021
- id
- 8e39cc93-fb86-4ca4-867d-06382058650c
- date added to LUP
- 2022-02-24 14:41:35
- date last changed
- 2023-11-08 22:27:26
@article{8e39cc93-fb86-4ca4-867d-06382058650c,
abstract = {{<p>This work provides a new method to enhance endwall heat transfer of a sharp turn channel. Several longitudinal vortex generators (LVGs) at various spacing and aspect ratio are placed in parallel on the inner side of endwall in a sharp turn channel. Liquid crystal thermography, pressure difference measurements, and a statistical method are applied to analyze the thermal behavior, friction factor, and temperature uniformity on the endwall mounted with an array of LVGs. The Reynolds number are in the range of 10,000 to 20,000. A comparison between the novel designed endwall and conventional turbulators in the same U bend channel is also conducted. Results indicate that the local Nusselt number is greatly augmented with the application of LVGs on the endwall, especially at the downstream part of the endwall. The LVGs with an aspect ratio of 2 and a spacing of 20 mm (dense case) provides the optimal thermal characteristics. The optimal design provides augmentation of heat transfer rate and thermal performance factor by up to 35.1% and 25.5%, respectively. The endwall fitted with delta-winglet vortex generators is a promising enhanced heat transfer method compared with the conventional design available for the same U-duct model.</p>}},
author = {{Zhao, Zhiqi and Luo, Lei and Zhou, Xun and Wang, Songtao and Wang, Zhongqi and Sundén, Bengt}},
issn = {{0735-1933}},
keywords = {{enhanced heat transfer; heat exchanger; internal endwall; longitudinal vortex generator; two-pass turn channel}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{International Communications in Heat and Mass Transfer}},
title = {{Analysis of enhanced turbulent heat transfer in a sharp turn channel having novel designed endwall with longitudinal vortex generator}},
url = {{http://dx.doi.org/10.1016/j.icheatmasstransfer.2021.105874}},
doi = {{10.1016/j.icheatmasstransfer.2021.105874}},
volume = {{131}},
year = {{2022}},
}