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Effects of vortex generators on the jet impingement heat transfer at different cross-flow Reynolds numbers

Wang, Chenglong LU ; Lei, Luo LU ; Wang, Lei LU and Sundén, Bengt LU (2016) In International Journal of Heat and Mass Transfer 96. p.278-286
Abstract

Experiments are carried out to investigate the effects of vortex generators on the jet impingement heat transfer in cross-flow. This study is a continuation of our previous research (Wang et al., 2015). In the present paper, the jet Reynolds number is fixed at 15,000 and the cross-flow Reynolds number varies from 40,000 to 64,000. The nozzle-to-surface distance to jet diameter ratio is 4.0. A vortex generator pair (VGP), placed in the cross-flow channel and upstream of the jet exit, is to enhance the impingement heat transfer. Both delta winglet (DW) and rectangular winglet (RW) are applied with different heights. Measurements of detailed heat transfer distributions on the impingement wall are conducted. Results show that the presence... (More)

Experiments are carried out to investigate the effects of vortex generators on the jet impingement heat transfer in cross-flow. This study is a continuation of our previous research (Wang et al., 2015). In the present paper, the jet Reynolds number is fixed at 15,000 and the cross-flow Reynolds number varies from 40,000 to 64,000. The nozzle-to-surface distance to jet diameter ratio is 4.0. A vortex generator pair (VGP), placed in the cross-flow channel and upstream of the jet exit, is to enhance the impingement heat transfer. Both delta winglet (DW) and rectangular winglet (RW) are applied with different heights. Measurements of detailed heat transfer distributions on the impingement wall are conducted. Results show that the presence of VGP substantially augments the impingement heat transfer in cross-flow for all the cases, and its effect depends on the shape of the VGP, the height of the VGP, and also the cross-flow Reynolds number. The RW provides better heat transfer enhancement than the DW due to stronger vortical flow. The enhancement also increases monotonically with the height of the VGP. In addition, the averaged Nusselt number and pressure drop of the jet and cross-flow at different cross-flow Reynolds numbers are included. It is found that the favorable effects of the VGP are more significant as the cross-flow Reynolds number increases. Some PIV measurements were carried out. The flow structures and heat transfer mechanisms are discussed.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Cross-flow, Heat transfer enhancement, Jet impingement, Vortex generator
in
International Journal of Heat and Mass Transfer
volume
96
pages
9 pages
publisher
Pergamon
external identifiers
  • Scopus:84957043357
  • WOS:000371841900027
ISSN
0017-9310
DOI
10.1016/j.ijheatmasstransfer.2016.01.042
language
English
LU publication?
yes
id
9b5ac8b2-b30e-4a2b-9934-73469b055388
date added to LUP
2016-05-10 12:21:58
date last changed
2017-02-12 04:32:55
@article{9b5ac8b2-b30e-4a2b-9934-73469b055388,
  abstract     = {<p>Experiments are carried out to investigate the effects of vortex generators on the jet impingement heat transfer in cross-flow. This study is a continuation of our previous research (Wang et al., 2015). In the present paper, the jet Reynolds number is fixed at 15,000 and the cross-flow Reynolds number varies from 40,000 to 64,000. The nozzle-to-surface distance to jet diameter ratio is 4.0. A vortex generator pair (VGP), placed in the cross-flow channel and upstream of the jet exit, is to enhance the impingement heat transfer. Both delta winglet (DW) and rectangular winglet (RW) are applied with different heights. Measurements of detailed heat transfer distributions on the impingement wall are conducted. Results show that the presence of VGP substantially augments the impingement heat transfer in cross-flow for all the cases, and its effect depends on the shape of the VGP, the height of the VGP, and also the cross-flow Reynolds number. The RW provides better heat transfer enhancement than the DW due to stronger vortical flow. The enhancement also increases monotonically with the height of the VGP. In addition, the averaged Nusselt number and pressure drop of the jet and cross-flow at different cross-flow Reynolds numbers are included. It is found that the favorable effects of the VGP are more significant as the cross-flow Reynolds number increases. Some PIV measurements were carried out. The flow structures and heat transfer mechanisms are discussed.</p>},
  author       = {Wang, Chenglong and Lei, Luo and Wang, Lei and Sundén, Bengt},
  issn         = {0017-9310},
  keyword      = {Cross-flow,Heat transfer enhancement,Jet impingement,Vortex generator},
  language     = {eng},
  month        = {05},
  pages        = {278--286},
  publisher    = {Pergamon},
  series       = {International Journal of Heat and Mass Transfer},
  title        = {Effects of vortex generators on the jet impingement heat transfer at different cross-flow Reynolds numbers},
  url          = {http://dx.doi.org/10.1016/j.ijheatmasstransfer.2016.01.042},
  volume       = {96},
  year         = {2016},
}