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On the improvement of film cooling performance using tree-shaped network holes : A comparative study

Zhang, Guohua LU ; Liu, Jian LU ; Sundén, Bengt LU and Xie, Gongnan LU (2018) In Numerical Heat Transfer; Part A: Applications 74(4). p.1121-1138
Abstract

For modern high-efficiency gas turbines, film cooling is an essential method to protect the turbine blade from the hot gas, and the issue about how to improve the film cooling performance has attracted much attention. This study presents a new design concept used for film cooling in gas turbine to improve the overall cooling effectiveness and better decrease the metal temperature of the blade at the same time. A tree-shaped film cooling structure is considered. To validate the superiority of the proposed structure, a series of numerical simulation cases are conducted at three typical blowing ratios (i.e. 0.5, 0.764, and 0.9). The first case is a film cooling channel with a single film hole with a diameter of 5 mm and it is inclined by α... (More)

For modern high-efficiency gas turbines, film cooling is an essential method to protect the turbine blade from the hot gas, and the issue about how to improve the film cooling performance has attracted much attention. This study presents a new design concept used for film cooling in gas turbine to improve the overall cooling effectiveness and better decrease the metal temperature of the blade at the same time. A tree-shaped film cooling structure is considered. To validate the superiority of the proposed structure, a series of numerical simulation cases are conducted at three typical blowing ratios (i.e. 0.5, 0.764, and 0.9). The first case is a film cooling channel with a single film hole with a diameter of 5 mm and it is inclined by α = 45° relative to the mainstream direction and the other three cases are tree-shaped structures with one level, two levels and three levels of bifurcations. Moreover, the same boundary conditions and turbulence model (realizable k–ε) are adopted, and three-dimensional numerical simulations are used for all cases. The computed results show that the higher the blowing ratio, the better is the overall effectiveness downstream the film holes of the tree-shaped structures, whereas the opposite is valid for the case with a single film hole. Additionally, the overall effectiveness of the tree-shaped structures is improved more than 50% compared with Case 1 with a single film hole, and the results also demonstrate that the more levels of the structure, the lower the metal temperatures will be. Therefore, it is indicated that this research will make a contribution to a higher performance gas turbine.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Numerical Heat Transfer; Part A: Applications
volume
74
issue
4
pages
1121 - 1138
publisher
Taylor & Francis
external identifiers
  • scopus:85055336157
ISSN
1040-7782
DOI
10.1080/10407782.2018.1507886
language
English
LU publication?
yes
id
f4af574b-acde-49b9-9212-58344d071b77
date added to LUP
2018-11-19 10:26:47
date last changed
2021-10-10 04:46:48
@article{f4af574b-acde-49b9-9212-58344d071b77,
  abstract     = {<p>For modern high-efficiency gas turbines, film cooling is an essential method to protect the turbine blade from the hot gas, and the issue about how to improve the film cooling performance has attracted much attention. This study presents a new design concept used for film cooling in gas turbine to improve the overall cooling effectiveness and better decrease the metal temperature of the blade at the same time. A tree-shaped film cooling structure is considered. To validate the superiority of the proposed structure, a series of numerical simulation cases are conducted at three typical blowing ratios (i.e. 0.5, 0.764, and 0.9). The first case is a film cooling channel with a single film hole with a diameter of 5 mm and it is inclined by α = 45° relative to the mainstream direction and the other three cases are tree-shaped structures with one level, two levels and three levels of bifurcations. Moreover, the same boundary conditions and turbulence model (realizable k–ε) are adopted, and three-dimensional numerical simulations are used for all cases. The computed results show that the higher the blowing ratio, the better is the overall effectiveness downstream the film holes of the tree-shaped structures, whereas the opposite is valid for the case with a single film hole. Additionally, the overall effectiveness of the tree-shaped structures is improved more than 50% compared with Case 1 with a single film hole, and the results also demonstrate that the more levels of the structure, the lower the metal temperatures will be. Therefore, it is indicated that this research will make a contribution to a higher performance gas turbine.</p>},
  author       = {Zhang, Guohua and Liu, Jian and Sundén, Bengt and Xie, Gongnan},
  issn         = {1040-7782},
  language     = {eng},
  number       = {4},
  pages        = {1121--1138},
  publisher    = {Taylor & Francis},
  series       = {Numerical Heat Transfer; Part A: Applications},
  title        = {On the improvement of film cooling performance using tree-shaped network holes : A comparative study},
  url          = {http://dx.doi.org/10.1080/10407782.2018.1507886},
  doi          = {10.1080/10407782.2018.1507886},
  volume       = {74},
  year         = {2018},
}