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Investigation of heat transfer and fluid flow in fractal truncated ribbed channels for the internal cooling of turbine blades

Liu, Jian LU ; Hussain, Safeer LU ; Wang, Lei LU ; Xie, Gongnan LU and Sundén, Bengt LU (2018) 16th International Heat Transfer Conference, IHTC 2018 In International Heat Transfer Conference p.3239-3246
Abstract

Ribs are widely employed in internal cooling passages of turbine blades to enhance heat transfer. From the mathematics, a fractal is an abstract object used to describe naturally occurring objects which exhibits similar properties with increased smaller scales. In a ribbed channel, originating from two sides truncated ribs, fractal truncated ribs are built and the evolving process contains three sides truncated ribs, five sides truncated ribs, nine sides truncated ribs and seventeen sides truncated ribs. Steady Liquid Crystal Thermography (LCT) is employed to measure surface temperature and derive heat transfer coefficients over the ribbed surfaces in the tested channels. Turbulent flow details are presented by numerical calculations... (More)

Ribs are widely employed in internal cooling passages of turbine blades to enhance heat transfer. From the mathematics, a fractal is an abstract object used to describe naturally occurring objects which exhibits similar properties with increased smaller scales. In a ribbed channel, originating from two sides truncated ribs, fractal truncated ribs are built and the evolving process contains three sides truncated ribs, five sides truncated ribs, nine sides truncated ribs and seventeen sides truncated ribs. Steady Liquid Crystal Thermography (LCT) is employed to measure surface temperature and derive heat transfer coefficients over the ribbed surfaces in the tested channels. Turbulent flow details are presented by numerical calculations with an established turbulence model, i.e. the k-ω SST model. From the study, truncated ribs can enhance the heat transfer at the truncated gap regions. With the scale of fractal truncated ribs becoming smaller, the low heat transfer regions downstream the ribs are effectively reduced. With the evolving of the fractal truncated ribs, the shape of high heat transfer region behind single truncated part keeps similar. The truncated ribs change cause enhancement vortices in the spanwise direction and enlarge local heat transfer. The truncated ribs enhance heat transfer by reducing the recirculating flows and the cases with smaller scales have more uniform heat transfer distributions. With the scale of the fractal truncated ribs becoming smaller, the flow related terms, such as, pressure field, turbulent kinetic energy and vorticity magnitude, also become more uniform.

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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
Convection, Fractal, Gas turbine, Heat transfer enhancement, K-ω SST, LCT, Truncated ribs
host publication
Proceeding: International Heat Transfer Conference 16
series title
International Heat Transfer Conference
pages
8 pages
publisher
Begell House
conference name
16th International Heat Transfer Conference, IHTC 2018
conference location
Beijing, China
conference dates
2018-08-10 - 2018-08-15
external identifiers
  • scopus:85068351111
ISSN
2377-424X
DOI
10.1615/IHTC16.cov.022153
language
English
LU publication?
yes
id
5b4209e1-0753-4b67-a482-580b3aec15a5
date added to LUP
2019-07-11 15:00:48
date last changed
2019-08-06 03:24:20
@inproceedings{5b4209e1-0753-4b67-a482-580b3aec15a5,
  abstract     = {<p>Ribs are widely employed in internal cooling passages of turbine blades to enhance heat transfer. From the mathematics, a fractal is an abstract object used to describe naturally occurring objects which exhibits similar properties with increased smaller scales. In a ribbed channel, originating from two sides truncated ribs, fractal truncated ribs are built and the evolving process contains three sides truncated ribs, five sides truncated ribs, nine sides truncated ribs and seventeen sides truncated ribs. Steady Liquid Crystal Thermography (LCT) is employed to measure surface temperature and derive heat transfer coefficients over the ribbed surfaces in the tested channels. Turbulent flow details are presented by numerical calculations with an established turbulence model, i.e. the k-ω SST model. From the study, truncated ribs can enhance the heat transfer at the truncated gap regions. With the scale of fractal truncated ribs becoming smaller, the low heat transfer regions downstream the ribs are effectively reduced. With the evolving of the fractal truncated ribs, the shape of high heat transfer region behind single truncated part keeps similar. The truncated ribs change cause enhancement vortices in the spanwise direction and enlarge local heat transfer. The truncated ribs enhance heat transfer by reducing the recirculating flows and the cases with smaller scales have more uniform heat transfer distributions. With the scale of the fractal truncated ribs becoming smaller, the flow related terms, such as, pressure field, turbulent kinetic energy and vorticity magnitude, also become more uniform.</p>},
  author       = {Liu, Jian and Hussain, Safeer and Wang, Lei and Xie, Gongnan and Sundén, Bengt},
  booktitle    = {International Heat Transfer Conference},
  issn         = {2377-424X},
  keyword      = {Convection,Fractal,Gas turbine,Heat transfer enhancement,K-ω SST,LCT,Truncated ribs},
  language     = {eng},
  location     = {Beijing, China},
  pages        = {3239--3246},
  publisher    = {Begell House},
  title        = {Investigation of heat transfer and fluid flow in fractal truncated ribbed channels for the internal cooling of turbine blades},
  url          = {http://dx.doi.org/10.1615/IHTC16.cov.022153},
  year         = {2018},
}