ENDWALL HEAT TRANSFER AT THE TURN SECTION IN A TWO-PASS SQUARE CHANNEL WITH AND WITHOUT RIBS
(2013) In Journal of Enhanced Heat Transfer 20(4). p.321-332- Abstract
- The endwall heat transfer characteristics at the turn section in a two-pass square channel have been examined experimentally using a liquid crystal thermal imaging technique. The effects of periodic ribs on the endwall heat transfer are also discussed. Results indicate that the heat transfer at the turn section in the absence of ribs is dominated by the flow impingement. Close to the impingement region, the Nusselt number is scaled by Re-0.56; further downstream, the scaling factor changes to Re-0.62. The heat transfer distribution on the endwall is not monotonic and a local minimum region is observed. It is believed that the local minimum region is associated with the transition between two regimes with distinct turbulence levels. In the... (More)
- The endwall heat transfer characteristics at the turn section in a two-pass square channel have been examined experimentally using a liquid crystal thermal imaging technique. The effects of periodic ribs on the endwall heat transfer are also discussed. Results indicate that the heat transfer at the turn section in the absence of ribs is dominated by the flow impingement. Close to the impingement region, the Nusselt number is scaled by Re-0.56; further downstream, the scaling factor changes to Re-0.62. The heat transfer distribution on the endwall is not monotonic and a local minimum region is observed. It is believed that the local minimum region is associated with the transition between two regimes with distinct turbulence levels. In the presence of ribs, the heat transfer patterns are significantly altered. Due to the increased turbulence levels induced by the protrusion of ribs, the local minimum Nu region cannot be detected. In addition, thermal performance is evaluated based on the constant flow rate and pumping power criteria. It is found that the highest heat transfer enhancement factor is obtained at a rib pitch ratio of 12. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/4656028
- author
- Wang, Lei LU ; Ghorbani-Tari, Zahra LU ; Wang, Chenglong LU ; Wu, Zan LU and Sundén, Bengt LU
- organization
- publishing date
- 2013
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- rough surface, structured ribs, single-phase flow, gas turbine, liquid, crystal method
- in
- Journal of Enhanced Heat Transfer
- volume
- 20
- issue
- 4
- pages
- 321 - 332
- publisher
- Begell House
- external identifiers
-
- wos:000340978800003
- scopus:84906705425
- ISSN
- 1563-5074
- DOI
- 10.1615/JEnhHeatTransf.2014010077
- language
- English
- LU publication?
- yes
- id
- 3a570251-c0bd-4b5d-ac1c-f6022e1bafb6 (old id 4656028)
- date added to LUP
- 2016-04-01 10:06:07
- date last changed
- 2022-03-27 04:51:06
@article{3a570251-c0bd-4b5d-ac1c-f6022e1bafb6,
abstract = {{The endwall heat transfer characteristics at the turn section in a two-pass square channel have been examined experimentally using a liquid crystal thermal imaging technique. The effects of periodic ribs on the endwall heat transfer are also discussed. Results indicate that the heat transfer at the turn section in the absence of ribs is dominated by the flow impingement. Close to the impingement region, the Nusselt number is scaled by Re-0.56; further downstream, the scaling factor changes to Re-0.62. The heat transfer distribution on the endwall is not monotonic and a local minimum region is observed. It is believed that the local minimum region is associated with the transition between two regimes with distinct turbulence levels. In the presence of ribs, the heat transfer patterns are significantly altered. Due to the increased turbulence levels induced by the protrusion of ribs, the local minimum Nu region cannot be detected. In addition, thermal performance is evaluated based on the constant flow rate and pumping power criteria. It is found that the highest heat transfer enhancement factor is obtained at a rib pitch ratio of 12.}},
author = {{Wang, Lei and Ghorbani-Tari, Zahra and Wang, Chenglong and Wu, Zan and Sundén, Bengt}},
issn = {{1563-5074}},
keywords = {{rough surface; structured ribs; single-phase flow; gas turbine; liquid; crystal method}},
language = {{eng}},
number = {{4}},
pages = {{321--332}},
publisher = {{Begell House}},
series = {{Journal of Enhanced Heat Transfer}},
title = {{ENDWALL HEAT TRANSFER AT THE TURN SECTION IN A TWO-PASS SQUARE CHANNEL WITH AND WITHOUT RIBS}},
url = {{http://dx.doi.org/10.1615/JEnhHeatTransf.2014010077}},
doi = {{10.1615/JEnhHeatTransf.2014010077}},
volume = {{20}},
year = {{2013}},
}