Full Content is available to subscribers

Subscribe/Learn More  >

Predictions of Cooling From Dirt Purge Holes Along the Tip of a Turbine Blade

[+] Author Affiliations
E. M. Hohlfeld, J. R. Christophel, E. L. Couch, K. A. Thole

Virginia Polytechnic Institute and State University, Blacksburg, VA

Paper No. GT2003-38251, pp. 153-162; 10 pages
  • ASME Turbo Expo 2003, collocated with the 2003 International Joint Power Generation Conference
  • Volume 5: Turbo Expo 2003, Parts A and B
  • Atlanta, Georgia, USA, June 16–19, 2003
  • Conference Sponsors: International Gas Turbine Institute
  • ISBN: 0-7918-3688-6 | eISBN: 0-7918-3671-1
  • Copyright © 2003 by ASME


The clearance gap between the tip of a turbine blade and its associated shroud provides a flow path for leakage from the pressure side of the blade to the suction side. The tip region is one area that experiences high heat transfer and, as such, can be the determining factor for blade life. One method for reducing blade tip heat transfer is to use cooler fluid from the compressor, that exits from relatively large dirt purge holes placed in the tip, for cooling purposes. Dirt purge holes are typically manufactured in the blade tip to extract dirt from the coolant flow through centrifugal forces such that these dirt particles do not block smaller diameter film-cooling holes. This paper discusses the results of numerous computational simulations of cooling injection from dirt purge holes along the tip of a turbine blade. Some comparisons are also made to experimental results in which a properly scaled-up blade geometry (12X) was used to form a two-passage linear cascade. Computational results indicate that the cooling achieved through the dirt purge injection from the blade tip is dependent on the gap size as well as the blowing ratio. For a small tip gap (0.54% of the span) the flow exiting the dirt purge holes act as a blockage for the leakage flow across the gap. As the blowing ratio is increased for a large tip gap (1.63% of the span), the tip cooling increases only slightly while the cooling to the shroud increases significantly.

Copyright © 2003 by ASME



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

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 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