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Computational investigation of dimple effects on heat transfer and friction factor in a Lamilloy cooling structure

Lei, Luo LU ; Wang, Chenglong LU ; Wang, Lei LU ; Sundén, Bengt LU and Wang, Songtao (2015) In Journal of Enhanced Heat Transfer 22(2). p.147-175
Abstract
Good heat transfer performance with a moderate pressure drop penalty contributes to the gas turbine engine lifetime and guaranteeing engine efficiency. In this study, the dimple effects for a Lamilloy (R) (Allison Advanced Development Corporation, Indiana, IN, USA) cooling structure on the heat transfer and friction factor are numerically investigated. The dimple is positioned directly under the jet impingement nozzle. The Reynolds number ranges from 10,000 to 70,000, the dimple normalized depth is between 0 and 0.3, and the dimple normalized diameter varies from 1 to 2.5. The results for the flow field, target surface heat transfer, pin fin surface heat transfer, friction factor, and solid domain outer-wall temperature are included. For... (More)
Good heat transfer performance with a moderate pressure drop penalty contributes to the gas turbine engine lifetime and guaranteeing engine efficiency. In this study, the dimple effects for a Lamilloy (R) (Allison Advanced Development Corporation, Indiana, IN, USA) cooling structure on the heat transfer and friction factor are numerically investigated. The dimple is positioned directly under the jet impingement nozzle. The Reynolds number ranges from 10,000 to 70,000, the dimple normalized depth is between 0 and 0.3, and the dimple normalized diameter varies from 1 to 2.5. The results for the flow field, target surface heat transfer, pin fin surface heat transfer, friction factor, and solid domain outer-wall temperature are included. For comparison, a Lamilloy cooling structure without the dimple is considered as the baseline. The results show that the dimple significantly increases the local heat transfer due to flow reattachment and recirculation. With an increase in the normalized dimple depth, the heat transfer on the target surface is first augmented due to the increase of flow reattachment and recirculation, and then it is decreased due to the large toroidal vortex. However, an increase in the dimple depth results in reduction of the pin fin surface heat transfer. As the dimple diameter increases, the target surface heat transfer is also first augmented due to the increase in the flow reattachment and recirculation, and then it is decreased as the flow separation increases. The thermal performance indicates that the intensity of the heat transfer enhancement depends on the depth and diameter of the dimple. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
structured roughness, dimple depth-to-diameter ratio, extended surface, jet impingement, single-phase flows, gas-turbine cooling
in
Journal of Enhanced Heat Transfer
volume
22
issue
2
pages
147 - 175
publisher
Begell House
external identifiers
  • wos:000367104500004
  • scopus:84953256625
ISSN
1563-5074
DOI
10.1615/JEnhHeatTransf.2015013956
language
English
LU publication?
yes
id
4224b15a-315d-4d22-9657-18bf18efcb9a (old id 8548767)
date added to LUP
2016-01-29 08:23:00
date last changed
2017-07-23 03:28:06
@article{4224b15a-315d-4d22-9657-18bf18efcb9a,
  abstract     = {Good heat transfer performance with a moderate pressure drop penalty contributes to the gas turbine engine lifetime and guaranteeing engine efficiency. In this study, the dimple effects for a Lamilloy (R) (Allison Advanced Development Corporation, Indiana, IN, USA) cooling structure on the heat transfer and friction factor are numerically investigated. The dimple is positioned directly under the jet impingement nozzle. The Reynolds number ranges from 10,000 to 70,000, the dimple normalized depth is between 0 and 0.3, and the dimple normalized diameter varies from 1 to 2.5. The results for the flow field, target surface heat transfer, pin fin surface heat transfer, friction factor, and solid domain outer-wall temperature are included. For comparison, a Lamilloy cooling structure without the dimple is considered as the baseline. The results show that the dimple significantly increases the local heat transfer due to flow reattachment and recirculation. With an increase in the normalized dimple depth, the heat transfer on the target surface is first augmented due to the increase of flow reattachment and recirculation, and then it is decreased due to the large toroidal vortex. However, an increase in the dimple depth results in reduction of the pin fin surface heat transfer. As the dimple diameter increases, the target surface heat transfer is also first augmented due to the increase in the flow reattachment and recirculation, and then it is decreased as the flow separation increases. The thermal performance indicates that the intensity of the heat transfer enhancement depends on the depth and diameter of the dimple.},
  author       = {Lei, Luo and Wang, Chenglong and Wang, Lei and Sundén, Bengt and Wang, Songtao},
  issn         = {1563-5074},
  keyword      = {structured roughness,dimple depth-to-diameter ratio,extended surface,jet impingement,single-phase flows,gas-turbine cooling},
  language     = {eng},
  number       = {2},
  pages        = {147--175},
  publisher    = {Begell House},
  series       = {Journal of Enhanced Heat Transfer},
  title        = {Computational investigation of dimple effects on heat transfer and friction factor in a Lamilloy cooling structure},
  url          = {http://dx.doi.org/10.1615/JEnhHeatTransf.2015013956},
  volume       = {22},
  year         = {2015},
}