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On the solar receiver thermal enhancement by using the dimple combined with delta winglet vortex generator

Lei, Luo LU ; Wen, Fengbo; Wang, Lei LU ; Sundén, Bengt LU and Wang, Songtao (2017) In Applied Thermal Engineering 111. p.586-598
Abstract

In this study, effects of dimples and their arrangement on the flow structure, heat transfer and friction factor in a solar receiver heated channel with delta-winglet vortex generators (DWVGs) are numerically studied. The dimples are placed either in an inline or a staggered layout. A smooth channel with pure dimples and a smooth channel with pure DWVGs are studied, in which the smooth channel with DWVGs is considered as baseline. The Reynolds number is ranging from 4000 to 40,000. Results of the flow structure, heat plate Nu number, friction factor, temperature and turbulent kinetic energy (TKE) are included. The results show that the adoption of dimples significantly impacts the flow structure by interacting with the vortex which is... (More)

In this study, effects of dimples and their arrangement on the flow structure, heat transfer and friction factor in a solar receiver heated channel with delta-winglet vortex generators (DWVGs) are numerically studied. The dimples are placed either in an inline or a staggered layout. A smooth channel with pure dimples and a smooth channel with pure DWVGs are studied, in which the smooth channel with DWVGs is considered as baseline. The Reynolds number is ranging from 4000 to 40,000. Results of the flow structure, heat plate Nu number, friction factor, temperature and turbulent kinetic energy (TKE) are included. The results show that the adoption of dimples significantly impacts the flow structure by interacting with the vortex which is generated by the DWVGs. A small part of the vortex moves downward and impinges on the inline arranged dimpled surface, which is beneficial for the heat transfer enhancement. However, for the staggered arrangement of dimples, the vortex flow is lifted upward before it impinges on the dimple surface. In this case, the inline arrangement dimples provides the best mixing and the highest heat transfer performance. The heat transfer is augmented by 36.23% while the friction factor is increased by 36.29% compared to the Baseline, respectively. The thermal performance analysis indicates that the use of dimples increases the thermal performance by 28.50%. It is also found that the adoption of inline dimples contributes to the optimal thermal performance and mixing of the cold and hot fluid.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Delta-winglet vortex generator, Dimples, Inline and staggered layout, Solar receiver, Thermal enhancement
in
Applied Thermal Engineering
volume
111
pages
13 pages
publisher
Elsevier
external identifiers
  • Scopus:84989201900
ISSN
1359-4311
DOI
10.1016/j.applthermaleng.2016.09.096
language
English
LU publication?
yes
id
0159bf7f-24c1-42d1-9b90-9a5a772a0f73
date added to LUP
2016-10-18 13:31:57
date last changed
2017-01-01 08:37:08
@article{0159bf7f-24c1-42d1-9b90-9a5a772a0f73,
  abstract     = {<p>In this study, effects of dimples and their arrangement on the flow structure, heat transfer and friction factor in a solar receiver heated channel with delta-winglet vortex generators (DWVGs) are numerically studied. The dimples are placed either in an inline or a staggered layout. A smooth channel with pure dimples and a smooth channel with pure DWVGs are studied, in which the smooth channel with DWVGs is considered as baseline. The Reynolds number is ranging from 4000 to 40,000. Results of the flow structure, heat plate Nu number, friction factor, temperature and turbulent kinetic energy (TKE) are included. The results show that the adoption of dimples significantly impacts the flow structure by interacting with the vortex which is generated by the DWVGs. A small part of the vortex moves downward and impinges on the inline arranged dimpled surface, which is beneficial for the heat transfer enhancement. However, for the staggered arrangement of dimples, the vortex flow is lifted upward before it impinges on the dimple surface. In this case, the inline arrangement dimples provides the best mixing and the highest heat transfer performance. The heat transfer is augmented by 36.23% while the friction factor is increased by 36.29% compared to the Baseline, respectively. The thermal performance analysis indicates that the use of dimples increases the thermal performance by 28.50%. It is also found that the adoption of inline dimples contributes to the optimal thermal performance and mixing of the cold and hot fluid.</p>},
  author       = {Lei, Luo and Wen, Fengbo and Wang, Lei and Sundén, Bengt and Wang, Songtao},
  issn         = {1359-4311},
  keyword      = {Delta-winglet vortex generator,Dimples,Inline and staggered layout,Solar receiver,Thermal enhancement},
  language     = {eng},
  month        = {01},
  pages        = {586--598},
  publisher    = {Elsevier},
  series       = {Applied Thermal Engineering},
  title        = {On the solar receiver thermal enhancement by using the dimple combined with delta winglet vortex generator},
  url          = {http://dx.doi.org/10.1016/j.applthermaleng.2016.09.096},
  volume       = {111},
  year         = {2017},
}