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Enhanced Internal Heat Transfer on the Tip-Wall in a Rectangular Two-Pass Channel (AR=1:2) by Pin-Fin Arrays

Xie, Gongnan LU ; Sundén, Bengt LU ; Wang, Lieke LU and Utriainen, Esa (2009) In Numerical Heat Transfer Part A: Applications 55(8). p.739-761
Abstract
To improve gas turbine performance, the operating temperature has been increased continuously. However, the heat transferred to the turbine blade is substantially increased as the turbine inlet temperature is increased. Cooling methods are therefore much needed for the turbine blades to ensure a long durability and safe operation. The blade tip region is exposed to the hot gas flows and is difficult to cool. A common way to cool the tip is to use serpentine passages with a 180 turn under the blade tip cap taking advantage of the three-dimensional turning effect and impingement. Increasing internal convective cooling is however required to increase the blade tip life. In this article, enhanced heat transfer of a blade tip has been... (More)
To improve gas turbine performance, the operating temperature has been increased continuously. However, the heat transferred to the turbine blade is substantially increased as the turbine inlet temperature is increased. Cooling methods are therefore much needed for the turbine blades to ensure a long durability and safe operation. The blade tip region is exposed to the hot gas flows and is difficult to cool. A common way to cool the tip is to use serpentine passages with a 180 turn under the blade tip cap taking advantage of the three-dimensional turning effect and impingement. Increasing internal convective cooling is however required to increase the blade tip life. In this article, enhanced heat transfer of a blade tip has been investigated numerically. The computational models consist of a two-pass channel with a 180 turn and arrays of pin-fins mounted on the tip-cap, and a smooth two-pass channel. Inlet Reynolds numbers range from 100,000 to 600,000. The computations are 3-D, steady, and incompressible. The detailed 3-D fluid flow and heat transfer over the tip surfaces are presented. The overall performance of the two models is evaluated. It is found that due to the combination of turning, impingement, and pin-fin crossflow the heat transfer coefficient of the pin-finned tip might be a factor of 1.84 higher than that of a smooth tip. This augmentation is achieved at the expense of a penalty of pressure drop around 35%. It is suggested that the pin-fins could be used to enhance blade tip heat transfer and cooling. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Numerical Heat Transfer Part A: Applications
volume
55
issue
8
pages
739 - 761
publisher
Taylor & Francis
external identifiers
  • wos:000265369500002
  • scopus:67651221856
ISSN
1040-7782
DOI
10.1080/10407780902864680
language
English
LU publication?
yes
id
6346c0de-6244-4491-a4f3-55ce535c612a (old id 1427866)
date added to LUP
2009-06-25 14:04:47
date last changed
2017-08-06 04:21:37
@article{6346c0de-6244-4491-a4f3-55ce535c612a,
  abstract     = {To improve gas turbine performance, the operating temperature has been increased continuously. However, the heat transferred to the turbine blade is substantially increased as the turbine inlet temperature is increased. Cooling methods are therefore much needed for the turbine blades to ensure a long durability and safe operation. The blade tip region is exposed to the hot gas flows and is difficult to cool. A common way to cool the tip is to use serpentine passages with a 180 turn under the blade tip cap taking advantage of the three-dimensional turning effect and impingement. Increasing internal convective cooling is however required to increase the blade tip life. In this article, enhanced heat transfer of a blade tip has been investigated numerically. The computational models consist of a two-pass channel with a 180 turn and arrays of pin-fins mounted on the tip-cap, and a smooth two-pass channel. Inlet Reynolds numbers range from 100,000 to 600,000. The computations are 3-D, steady, and incompressible. The detailed 3-D fluid flow and heat transfer over the tip surfaces are presented. The overall performance of the two models is evaluated. It is found that due to the combination of turning, impingement, and pin-fin crossflow the heat transfer coefficient of the pin-finned tip might be a factor of 1.84 higher than that of a smooth tip. This augmentation is achieved at the expense of a penalty of pressure drop around 35%. It is suggested that the pin-fins could be used to enhance blade tip heat transfer and cooling.},
  author       = {Xie, Gongnan and Sundén, Bengt and Wang, Lieke and Utriainen, Esa},
  issn         = {1040-7782},
  language     = {eng},
  number       = {8},
  pages        = {739--761},
  publisher    = {Taylor & Francis},
  series       = {Numerical Heat Transfer Part A: Applications},
  title        = {Enhanced Internal Heat Transfer on the Tip-Wall in a Rectangular Two-Pass Channel (AR=1:2) by Pin-Fin Arrays},
  url          = {http://dx.doi.org/10.1080/10407780902864680},
  volume       = {55},
  year         = {2009},
}