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Enhanced heat transfer in a labyrinth channels with ribs of different shape

Du, Wei LU ; Luo, Lei ; Wang, Songtao ; Liu, Jian LU and Sunden, Bengt Ake LU (2020) In International Journal of Numerical Methods for Heat and Fluid Flow 30(2). p.724-741
Abstract

Purpose: The purpose of this study is to enhance the thermal performance in the labyrinth channel by different ribs shape. The labyrinth channel is a relatively new cooling structure to decrease the temperature near the trailing region of gas turbine. Design/methodology/approach: Based on the geometric similarity, a simplified geometric model is used. The k − ω turbulence model is used to close the Navier–Stokes equations. Five rib shapes (one rectangular rib, two arched ribs and two trapezoid ribs) and five Reynolds numbers (10,000 to 50,000) are considered. The Nusselt number, flow structure and friction factor are analyzed. Findings: Nusselt number is tightly related to the rib shape in the labyrinth channel. The different shapes of... (More)

Purpose: The purpose of this study is to enhance the thermal performance in the labyrinth channel by different ribs shape. The labyrinth channel is a relatively new cooling structure to decrease the temperature near the trailing region of gas turbine. Design/methodology/approach: Based on the geometric similarity, a simplified geometric model is used. The k − ω turbulence model is used to close the Navier–Stokes equations. Five rib shapes (one rectangular rib, two arched ribs and two trapezoid ribs) and five Reynolds numbers (10,000 to 50,000) are considered. The Nusselt number, flow structure and friction factor are analyzed. Findings: Nusselt number is tightly related to the rib shape in the labyrinth channel. The different shapes of the ribs result in different horseshoe vortex and wake region. In general, the arched rib brings the highest Nusselt number and friction factor. The Nusselt number is increased by 15.8 per cent compared to that of trapezoidal ribs. High Nusselt number is accompanied by the high friction factor in a labyrinth channels. The friction factor is increased by 64.6 per cent compared to rectangular ribs. However, the rib shape has a minor effect on the overall thermal performance. Practical implications: This study is useful to protect the trailing region of advanced gas turbine. Originality/value: This paper presents the flow structure and heat transfer characteristics in a labyrinth channel with different rib shapes.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Heat transfer, Labyrinth channel, Rib shape, Thermal performance, Vortex
in
International Journal of Numerical Methods for Heat and Fluid Flow
volume
30
issue
2
pages
18 pages
publisher
Emerald Group Publishing Limited
external identifiers
  • scopus:85071653205
ISSN
0961-5539
DOI
10.1108/HFF-05-2019-0393
language
English
LU publication?
yes
id
b69ec978-0f91-4f49-aee0-dbcbbd7548f7
date added to LUP
2019-09-27 09:34:18
date last changed
2020-02-07 09:20:01
@article{b69ec978-0f91-4f49-aee0-dbcbbd7548f7,
  abstract     = {<p>Purpose: The purpose of this study is to enhance the thermal performance in the labyrinth channel by different ribs shape. The labyrinth channel is a relatively new cooling structure to decrease the temperature near the trailing region of gas turbine. Design/methodology/approach: Based on the geometric similarity, a simplified geometric model is used. The k − ω turbulence model is used to close the Navier–Stokes equations. Five rib shapes (one rectangular rib, two arched ribs and two trapezoid ribs) and five Reynolds numbers (10,000 to 50,000) are considered. The Nusselt number, flow structure and friction factor are analyzed. Findings: Nusselt number is tightly related to the rib shape in the labyrinth channel. The different shapes of the ribs result in different horseshoe vortex and wake region. In general, the arched rib brings the highest Nusselt number and friction factor. The Nusselt number is increased by 15.8 per cent compared to that of trapezoidal ribs. High Nusselt number is accompanied by the high friction factor in a labyrinth channels. The friction factor is increased by 64.6 per cent compared to rectangular ribs. However, the rib shape has a minor effect on the overall thermal performance. Practical implications: This study is useful to protect the trailing region of advanced gas turbine. Originality/value: This paper presents the flow structure and heat transfer characteristics in a labyrinth channel with different rib shapes.</p>},
  author       = {Du, Wei and Luo, Lei and Wang, Songtao and Liu, Jian and Sunden, Bengt Ake},
  issn         = {0961-5539},
  language     = {eng},
  number       = {2},
  pages        = {724--741},
  publisher    = {Emerald Group Publishing Limited},
  series       = {International Journal of Numerical Methods for Heat and Fluid Flow},
  title        = {Enhanced heat transfer in a labyrinth channels with ribs of different shape},
  url          = {http://dx.doi.org/10.1108/HFF-05-2019-0393},
  doi          = {10.1108/HFF-05-2019-0393},
  volume       = {30},
  year         = {2020},
}