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Numerical simulations of flow structure and turbulent heat transfer in a square ribbed channel with varying rib pitch ratio

Khalid, Aayan; Xie, Gongnan LU and Sunden, Bengt LU (2016) In Journal of Enhanced Heat Transfer 23(2). p.155-174
Abstract

In the fast development of advanced gas turbines with increasing output power, the inlet temperature is accordingly increased. Traditional cooling techniques failed to deal with such situations; however, new cooling techniques incorporating ribbed microchannels with higher capability of heat removal are required. In the present research, a square ribbed channel with various rib pitch ratios is designed to regulate the most optimum configuration for augmenting heat transfer rates to diminish pressure drop consequences. The inlet Reynolds number used for the microchannels varies from 20,000 to 160,000. Four different configurations of six continuous ribs are mounted on one wall by varying height and distance between the ribs. By using... (More)

In the fast development of advanced gas turbines with increasing output power, the inlet temperature is accordingly increased. Traditional cooling techniques failed to deal with such situations; however, new cooling techniques incorporating ribbed microchannels with higher capability of heat removal are required. In the present research, a square ribbed channel with various rib pitch ratios is designed to regulate the most optimum configuration for augmenting heat transfer rates to diminish pressure drop consequences. The inlet Reynolds number used for the microchannels varies from 20,000 to 160,000. Four different configurations of six continuous ribs are mounted on one wall by varying height and distance between the ribs. By using computational fluid dynamics with the v2f turbulence model and a constant wall heat flux as the boundary condition on the surfaces, temperature field, local heat transfer, normalized heat transfer, and thermal performance are acquired. The overall performances of four tested ribbed microchannels are evaluated and compared. Numerical results predict that the use of increasing rib pitch ratio in the same channel (case 3) is an appropriate design for enhancing heat transfer and reducing pressure loss. Although it has a lower friction factor compared to other cases, it gives the best performance of heat transfer enhancement. It is suggested that the ribbed microchannels with varying rib pitch ratio can increase the overall heat transfer performance.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Extended surface, Overall thermal performance, Passive technique, Recirculating flow, Single-phase flow, Structured surface
in
Journal of Enhanced Heat Transfer
volume
23
issue
2
pages
20 pages
publisher
Begell House
external identifiers
  • scopus:85028460087
ISSN
1065-5131
DOI
10.1615/JEnhHeatTransf.2017018645
language
English
LU publication?
yes
id
3535d24c-e2ac-4ec6-99e8-efa8d306b43f
date added to LUP
2017-09-25 11:00:54
date last changed
2017-09-25 11:00:54
@article{3535d24c-e2ac-4ec6-99e8-efa8d306b43f,
  abstract     = {<p>In the fast development of advanced gas turbines with increasing output power, the inlet temperature is accordingly increased. Traditional cooling techniques failed to deal with such situations; however, new cooling techniques incorporating ribbed microchannels with higher capability of heat removal are required. In the present research, a square ribbed channel with various rib pitch ratios is designed to regulate the most optimum configuration for augmenting heat transfer rates to diminish pressure drop consequences. The inlet Reynolds number used for the microchannels varies from 20,000 to 160,000. Four different configurations of six continuous ribs are mounted on one wall by varying height and distance between the ribs. By using computational fluid dynamics with the v<sup>2</sup>f turbulence model and a constant wall heat flux as the boundary condition on the surfaces, temperature field, local heat transfer, normalized heat transfer, and thermal performance are acquired. The overall performances of four tested ribbed microchannels are evaluated and compared. Numerical results predict that the use of increasing rib pitch ratio in the same channel (case 3) is an appropriate design for enhancing heat transfer and reducing pressure loss. Although it has a lower friction factor compared to other cases, it gives the best performance of heat transfer enhancement. It is suggested that the ribbed microchannels with varying rib pitch ratio can increase the overall heat transfer performance.</p>},
  author       = {Khalid, Aayan and Xie, Gongnan and Sunden, Bengt},
  issn         = {1065-5131},
  keyword      = {Extended surface,Overall thermal performance,Passive technique,Recirculating flow,Single-phase flow,Structured surface},
  language     = {eng},
  number       = {2},
  pages        = {155--174},
  publisher    = {Begell House},
  series       = {Journal of Enhanced Heat Transfer},
  title        = {Numerical simulations of flow structure and turbulent heat transfer in a square ribbed channel with varying rib pitch ratio},
  url          = {http://dx.doi.org/10.1615/JEnhHeatTransf.2017018645},
  volume       = {23},
  year         = {2016},
}