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Experimental study on the augmented Nusselt number of the endwall through a square-sectioned sharp-turn channel using novel heat exchanger

Zhao, Zhiqi LU ; Luo, Lei ; Du, Wei LU ; Wang, Songtao ; Zhou, Xun and Sundén, Bengt LU (2022) In International Journal of Heat and Mass Transfer 192.
Abstract

Aquiring higher thermal efficiency with minimum energy consumption is the continuous pursuit of heat exchanger design. This work aims to demonstrate a novel enhanced heat exchange approach for a two-pass heat exchanger surface using four forms of a novel heat exchanger (nHEX), such as high straight and low curved turbulators, etc. The nHEXs are arranged parallel and equally spaced on the internal endwall. A comparison between current design and conventionally turbulated endwalls of sharp-turn channels is presented. The results indicate that the heat transfer rate is greatly augmented by inserting an array of nHEXs compared to a smooth endwall channel. The strategically placed vortex generators can improve the lowest heat transfer region... (More)

Aquiring higher thermal efficiency with minimum energy consumption is the continuous pursuit of heat exchanger design. This work aims to demonstrate a novel enhanced heat exchange approach for a two-pass heat exchanger surface using four forms of a novel heat exchanger (nHEX), such as high straight and low curved turbulators, etc. The nHEXs are arranged parallel and equally spaced on the internal endwall. A comparison between current design and conventionally turbulated endwalls of sharp-turn channels is presented. The results indicate that the heat transfer rate is greatly augmented by inserting an array of nHEXs compared to a smooth endwall channel. The strategically placed vortex generators can improve the lowest heat transfer region on the smooth endwall to achieve overall thermal enhancement and temperature uniformity. Among the studied geometries, higher height or straight forms of the nHEXs are prone to enhance endwall heat transfer. The high straight forms of the nHEXs provide the maximum improvement of the normalized Nusselt number and thermal enhancement factor in a sharp-turn channel, which are 32% and 18% higher than the corresponding values of the smooth endwall, respectively. This study proved the potential of an array of parallel nHEXs to provide endwall heat transfer enhancement in a sharp-turn channel with an acceptable pressure drop penalty.

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author
; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
180-deg sharp turn channel, endwall Nusselt number, liquid crystal thermography, novel heat exchanger
in
International Journal of Heat and Mass Transfer
volume
192
article number
122920
publisher
Pergamon Press Ltd.
external identifiers
  • scopus:85128960357
ISSN
0017-9310
DOI
10.1016/j.ijheatmasstransfer.2022.122920
language
English
LU publication?
yes
id
f0852706-40df-435e-a1e7-7ee27a330b97
date added to LUP
2022-07-01 13:41:46
date last changed
2022-07-01 13:41:46
@article{f0852706-40df-435e-a1e7-7ee27a330b97,
  abstract     = {{<p>Aquiring higher thermal efficiency with minimum energy consumption is the continuous pursuit of heat exchanger design. This work aims to demonstrate a novel enhanced heat exchange approach for a two-pass heat exchanger surface using four forms of a novel heat exchanger (nHEX), such as high straight and low curved turbulators, etc. The nHEXs are arranged parallel and equally spaced on the internal endwall. A comparison between current design and conventionally turbulated endwalls of sharp-turn channels is presented. The results indicate that the heat transfer rate is greatly augmented by inserting an array of nHEXs compared to a smooth endwall channel. The strategically placed vortex generators can improve the lowest heat transfer region on the smooth endwall to achieve overall thermal enhancement and temperature uniformity. Among the studied geometries, higher height or straight forms of the nHEXs are prone to enhance endwall heat transfer. The high straight forms of the nHEXs provide the maximum improvement of the normalized Nusselt number and thermal enhancement factor in a sharp-turn channel, which are 32% and 18% higher than the corresponding values of the smooth endwall, respectively. This study proved the potential of an array of parallel nHEXs to provide endwall heat transfer enhancement in a sharp-turn channel with an acceptable pressure drop penalty.</p>}},
  author       = {{Zhao, Zhiqi and Luo, Lei and Du, Wei and Wang, Songtao and Zhou, Xun and Sundén, Bengt}},
  issn         = {{0017-9310}},
  keywords     = {{180-deg sharp turn channel; endwall Nusselt number; liquid crystal thermography; novel heat exchanger}},
  language     = {{eng}},
  publisher    = {{Pergamon Press Ltd.}},
  series       = {{International Journal of Heat and Mass Transfer}},
  title        = {{Experimental study on the augmented Nusselt number of the endwall through a square-sectioned sharp-turn channel using novel heat exchanger}},
  url          = {{http://dx.doi.org/10.1016/j.ijheatmasstransfer.2022.122920}},
  doi          = {{10.1016/j.ijheatmasstransfer.2022.122920}},
  volume       = {{192}},
  year         = {{2022}},
}