0
TECHNICAL PAPERS

Effect of Hole Geometry on the Thermal Performance of Fan-Shaped Film Cooling Holes

[+] Author and Article Information
Michael Gritsch, Heinz Schär, Klaus Döbbeling

 ALSTOM (Switzerland) Ltd., Brown Boveri Str. 7, Baden 5401, Switzerland

Will Colban1

 ALSTOM (Switzerland) Ltd., Brown Boveri Str. 7, Baden 5401, Switzerland

1

Currently at the Mechanical Engineering Department, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061.

J. Turbomach 127(4), 718-725 (Apr 28, 2005) (8 pages) doi:10.1115/1.2019315 History: Received October 27, 2004; Revised April 28, 2005

This study evaluates the impact of typical cooling hole shape variations on the thermal performance of fan-shaped film holes. A comprehensive set of experimental test cases featuring 16 different film-cooling configurations with different hole shapes have been investigated. The shape variations investigated include hole inlet-to-outlet area ratio, hole coverage ratio, hole pitch ratio, hole length, and hole orientation (compound) angle. Flow conditions applied cover a wide range of film blowing ratios M=0.5 to 2.5 at an engine-representative density ratio DR=1.7. An infrared thermography data acquisition system is used for highly accurate and spatially resolved surface temperature mappings. Accurate local temperature data are achieved by an in situ calibration procedure with the help of thermocouples embedded in the test plate. Detailed film-cooling effectiveness distributions and discharge coefficients are used for evaluating the thermal performance of a row of fan-shaped film holes. An extensive variation of the main geometrical parameters describing a fan-shaped film-cooling hole is done to cover a wide range of typical film-cooling applications in current gas turbine engines. Within the range investigated, laterally averaged film-cooling effectiveness was found to show only limited sensitivity from variations of the hole geometry parameters. This offers the potential to tailor the hole geometry according to needs beyond pure cooling performance, e.g., manufacturing facilitations.

Copyright © 2005 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 4

Discharge coefficients for all holes investigated

Grahic Jump Location
Figure 5

Laterally averaged film-cooling effectiveness, comparison to literature data sets

Grahic Jump Location
Figure 6

Effect of hole-length-to-diameter ratio on laterally averaged film-cooling effectiveness

Grahic Jump Location
Figure 7

Effect of hole-pitch-to-diameter ratio on laterally averaged film-cooling effectiveness

Grahic Jump Location
Figure 8

Effect of hole-pitch-to-diameter ratio on laterally averaged film-cooling effectiveness, normalized

Grahic Jump Location
Figure 9

Effect of coverage ratio on laterally averaged film-cooling effectiveness at AR=2.5

Grahic Jump Location
Figure 10

Effect of coverage ratio on laterally averaged film-cooling effectiveness at AR=4.2

Grahic Jump Location
Figure 2

Local surface temperature distribution downstream of film ejection location, Config.D

Grahic Jump Location
Figure 3

Film-cooling hole geometry

Grahic Jump Location
Figure 11

Effect of area ratio on laterally averaged film-cooling effectiveness at C∕P=0.43

Grahic Jump Location
Figure 12

Effect of area ratio on laterally averaged film-cooling effectiveness at C∕P=0.63

Grahic Jump Location
Figure 13

Effect of compound angle on laterally averaged film-cooling effectiveness

Grahic Jump Location
Figure 14

Symmetric (left) and nonsymmetric diffuser portion of the film-cooling hole

Grahic Jump Location
Figure 15

Effect of compound angle diffusion on laterally averaged film-cooling effectiveness

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In