The Role of Rotor Tip Clearance on the Aerodynamic Interaction of a Last Gas Turbine Stage and an Exhaust Diffuser PUBLIC ACCESS

[+] Author Affiliations
Reinhard Willinger, Hermann Haselbacher

Technical University of Vienna, Austria

Paper No. 98-GT-094, pp. V001T01A030; 9 pages
  • ASME 1998 International Gas Turbine and Aeroengine Congress and Exhibition
  • Volume 1: Turbomachinery
  • Stockholm, Sweden, June 2–5, 1998
  • Conference Sponsors: International Gas Turbine Institute
  • ISBN: 978-0-7918-7862-0
  • Copyright © 1998 by ASME


An investigation of the aerodynamic interaction between a last gas turbine stage and an exhaust diffuser is presented. Special attention is given to the influence of the rotor tip gap on this interaction. Flow measurements downstream of a linear cascade of turbine blades with tip gap have been performed in a low speed cascade wind tunnel. The geometry of the cascade corresponds to the tip section of a gas turbine of fairly recent design. Five tip gaps lying in the typical range were investigated. The two essential results are the leakage loss and the underturning in the end wall region. The flow field of the turbine cascade supplied the inlet boundary condition for the subsequent numerical investigation of the flow field in an annular diffuser. The geometry of the annular diffuser is based on dimensions of exhaust diffusers of some heavy duty and aeroderivative gas turbines. The result of the investigation is the diffuser pressure recovery factor as a function of the gap of the upstream cascade. The results from the cascade measurements and the diffuser computations have then been coupled by means of an interaction model. For gaps of practical interest, specific work and efficiency of the last gas turbine stage followed by an exhaust diffuser are independent of the rotor gap.

Copyright © 1998 by ASME
This article is only available in the PDF format.



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