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Comparisons of Pins/Dimples/Protrusions Cooling Concepts for a Turbine Blade Tip-Wall at High Reynolds Numbers

Xie, Gongnan LU ; Sundén, Bengt LU and Zhang, Weihong (2011) 2nd International Conference on Thermal Issues in Emerging Technologies In Journal of Heat Transfer-Transactions of The Asme 133(6).
Abstract
The blade tip region encounters high thermal loads because of the hot gas leakage flows, and it must therefore be cooled to ensure a long durability and safe operation. A common way to cool a blade tip is to design serpentine passages with a 180 deg turns under the blade tip-cap inside the turbine blade. Improved internal convective cooling is therefore required to increase blade tip lifetime. Pins, dimples, and protrusions are well recognized as effective devices to augment heat transfer in various applications. In this paper, enhanced heat transfer of an internal blade tip-wall has been predicted numerically. The computational models consist of a two-pass channel with 180 deg turn and arrays of circular pins, hemispherical dimples, or... (More)
The blade tip region encounters high thermal loads because of the hot gas leakage flows, and it must therefore be cooled to ensure a long durability and safe operation. A common way to cool a blade tip is to design serpentine passages with a 180 deg turns under the blade tip-cap inside the turbine blade. Improved internal convective cooling is therefore required to increase blade tip lifetime. Pins, dimples, and protrusions are well recognized as effective devices to augment heat transfer in various applications. In this paper, enhanced heat transfer of an internal blade tip-wall has been predicted numerically. The computational models consist of a two-pass channel with 180 deg turn and arrays of circular pins, hemispherical dimples, or protrusions internally mounted on the tip-wall. Inlet Reynolds numbers are ranging from 100,000 to 600,000. The overall performance of the two-pass channels is evaluated. Numerical results show that the heat transfer enhancement of the pinned-tip is up to a factor of 3.0 higher than that of a smooth tip while the dimpled-tip and protruded-tip provide about 2.0 times higher heat transfer. These augmentations are achieved at the cost of an increase of pressure drop by less than 10%. By comparing the present cooling concepts with pins, dimples, and protrusions, it is shown that the pinned-tip exhibits best performance to improve the blade tip cooling. However, when disregarding the added active area and considering the added mechanical stress, it is suggested that the usage of dimples is more suitable to enhance blade tip cooling, especially at low Reynolds numbers. [DOI: 10.1115/1.4003558] (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
heat transfer enhancement, blade tip-wall, pins, dimples, protrusions, numerical simulation
in
Journal of Heat Transfer-Transactions of The Asme
volume
133
issue
6
publisher
American Society Of Mechanical Engineers (ASME)
conference name
2nd International Conference on Thermal Issues in Emerging Technologies
external identifiers
  • wos:000288217900013
  • scopus:79952753599
ISSN
0022-1481
DOI
10.1115/1.4003558
language
English
LU publication?
yes
id
a45391f3-e656-4265-a863-2f7be27ca322 (old id 1868339)
date added to LUP
2011-04-27 13:43:04
date last changed
2017-09-03 04:07:01
@inproceedings{a45391f3-e656-4265-a863-2f7be27ca322,
  abstract     = {The blade tip region encounters high thermal loads because of the hot gas leakage flows, and it must therefore be cooled to ensure a long durability and safe operation. A common way to cool a blade tip is to design serpentine passages with a 180 deg turns under the blade tip-cap inside the turbine blade. Improved internal convective cooling is therefore required to increase blade tip lifetime. Pins, dimples, and protrusions are well recognized as effective devices to augment heat transfer in various applications. In this paper, enhanced heat transfer of an internal blade tip-wall has been predicted numerically. The computational models consist of a two-pass channel with 180 deg turn and arrays of circular pins, hemispherical dimples, or protrusions internally mounted on the tip-wall. Inlet Reynolds numbers are ranging from 100,000 to 600,000. The overall performance of the two-pass channels is evaluated. Numerical results show that the heat transfer enhancement of the pinned-tip is up to a factor of 3.0 higher than that of a smooth tip while the dimpled-tip and protruded-tip provide about 2.0 times higher heat transfer. These augmentations are achieved at the cost of an increase of pressure drop by less than 10%. By comparing the present cooling concepts with pins, dimples, and protrusions, it is shown that the pinned-tip exhibits best performance to improve the blade tip cooling. However, when disregarding the added active area and considering the added mechanical stress, it is suggested that the usage of dimples is more suitable to enhance blade tip cooling, especially at low Reynolds numbers. [DOI: 10.1115/1.4003558]},
  author       = {Xie, Gongnan and Sundén, Bengt and Zhang, Weihong},
  booktitle    = {Journal of Heat Transfer-Transactions of The Asme},
  issn         = {0022-1481},
  keyword      = {heat transfer enhancement,blade tip-wall,pins,dimples,protrusions,numerical simulation},
  language     = {eng},
  number       = {6},
  publisher    = {American Society Of Mechanical Engineers (ASME)},
  title        = {Comparisons of Pins/Dimples/Protrusions Cooling Concepts for a Turbine Blade Tip-Wall at High Reynolds Numbers},
  url          = {http://dx.doi.org/10.1115/1.4003558},
  volume       = {133},
  year         = {2011},
}