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Computational analysis of span-wise hole locations on fluid flow and film cooling of internal channels with crescent ribs

Zhang, Guohua LU ; Liu, Xueting ; Sundén, Bengt Ake LU and Xie, Gongnan LU (2019) In International Journal of Numerical Methods for Heat and Fluid Flow 29(8). p.2728-2753
Abstract

Purpose: This study aims to clarify the mechanism of film hole location at the span-wise direction of an internal cooling channel with crescent ribs on the adiabatic film cooling performance, three configurations are designed to observe the effects of the distance between the center of the ellipse and the side wall(Case 1, l = w/2, Case 2, l = w/3 and for Case 3, l = w/4). Design/methodology/approach: Numerical simulations are conducted under two blowing ratios (i.e. 0.5 and 1) and a fixed cross-flow Reynolds number (Rec = 100,000) with a verified turbulence model. Findings: It is shown that at low blowing ratio, reducing the distance increases the film cooling effectiveness but keeps the trend of the effectiveness unchanged,... (More)

Purpose: This study aims to clarify the mechanism of film hole location at the span-wise direction of an internal cooling channel with crescent ribs on the adiabatic film cooling performance, three configurations are designed to observe the effects of the distance between the center of the ellipse and the side wall(Case 1, l = w/2, Case 2, l = w/3 and for Case 3, l = w/4). Design/methodology/approach: Numerical simulations are conducted under two blowing ratios (i.e. 0.5 and 1) and a fixed cross-flow Reynolds number (Rec = 100,000) with a verified turbulence model. Findings: It is shown that at low blowing ratio, reducing the distance increases the film cooling effectiveness but keeps the trend of the effectiveness unchanged, while at high blowing ratio, the characteristic is a little bit different in the range of 0 = x/D = 10. Research limitations/implications: These features could be explained by the fact that shrinking the distance between the hole and side wall induces a much smaller reserved region and vortex downstream the ribs and a lower resistance for cooling air entering the film hole. Furthermore, the spiral flow inside the hole is impaired. Originality/value: As a result, the kidney-shaped vortices originating from the jet flow are weakened, and the target surface can be well covered, resulting in an enhancement of the adiabatic film cooling performance.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Blowing ratio, Crescent rib, Film cooling effectiveness, Kidney-shaped vortices, Spanwise distance
in
International Journal of Numerical Methods for Heat and Fluid Flow
volume
29
issue
8
pages
2728 - 2753
publisher
Emerald Group Publishing Limited
external identifiers
  • scopus:85070413666
ISSN
0961-5539
DOI
10.1108/HFF-09-2018-0474
language
English
LU publication?
yes
id
4df022b4-584e-49ff-aac1-30e0ba2e7ae6
date added to LUP
2019-08-26 13:54:56
date last changed
2022-04-10 20:41:55
@article{4df022b4-584e-49ff-aac1-30e0ba2e7ae6,
  abstract     = {{<p>Purpose: This study aims to clarify the mechanism of film hole location at the span-wise direction of an internal cooling channel with crescent ribs on the adiabatic film cooling performance, three configurations are designed to observe the effects of the distance between the center of the ellipse and the side wall(Case 1, l = w/2, Case 2, l = w/3 and for Case 3, l = w/4). Design/methodology/approach: Numerical simulations are conducted under two blowing ratios (i.e. 0.5 and 1) and a fixed cross-flow Reynolds number (Re<sub>c</sub> = 100,000) with a verified turbulence model. Findings: It is shown that at low blowing ratio, reducing the distance increases the film cooling effectiveness but keeps the trend of the effectiveness unchanged, while at high blowing ratio, the characteristic is a little bit different in the range of 0 = x/D = 10. Research limitations/implications: These features could be explained by the fact that shrinking the distance between the hole and side wall induces a much smaller reserved region and vortex downstream the ribs and a lower resistance for cooling air entering the film hole. Furthermore, the spiral flow inside the hole is impaired. Originality/value: As a result, the kidney-shaped vortices originating from the jet flow are weakened, and the target surface can be well covered, resulting in an enhancement of the adiabatic film cooling performance.</p>}},
  author       = {{Zhang, Guohua and Liu, Xueting and Sundén, Bengt Ake and Xie, Gongnan}},
  issn         = {{0961-5539}},
  keywords     = {{Blowing ratio; Crescent rib; Film cooling effectiveness; Kidney-shaped vortices; Spanwise distance}},
  language     = {{eng}},
  number       = {{8}},
  pages        = {{2728--2753}},
  publisher    = {{Emerald Group Publishing Limited}},
  series       = {{International Journal of Numerical Methods for Heat and Fluid Flow}},
  title        = {{Computational analysis of span-wise hole locations on fluid flow and film cooling of internal channels with crescent ribs}},
  url          = {{http://dx.doi.org/10.1108/HFF-09-2018-0474}},
  doi          = {{10.1108/HFF-09-2018-0474}},
  volume       = {{29}},
  year         = {{2019}},
}