Experiments in Fluids

, 54:1462 | Cite as

Investigation of the tip leakage flow at turbine rotor blades with squealer cavity

  • Andreas Fischer
  • Jörg König
  • Jürgen Czarske
  • Clemens Rakenius
  • Gregor Schmid
  • Heinz-Peter Schiffer
Research Article
First Online:
Received:
Revised:
Accepted:

Abstract

Understanding of the tip leakage flow (TLF) in turbine rotors is one key aspect in the design for improving the efficiency of turbines. This requires measurements and simulations of the TLF, especially when investigating new rotor blade designs with blade tip treatments. However, flow measurements in the tip gap of a rotating machine are highly challenging because of the small gap size of about 1 mm and the high unsteadiness of the flow requiring a high temporal resolution of about 10 μs. For this purpose, an optimized non-intrusive measurement concept based on frequency modulated Doppler global velocimetry is presented, which fulfills the requirements. Three component velocity fields of the TLF were obtained in a turbine test rig at a blade passing frequency of 930 Hz. The rotor blades were equipped with a squealer tip, and the TLF in the squealer cavity region was successfully measured. The measurement agrees well with calculated results showing gradients in the tip gap above the squealer cavity. Furthermore, the development of the tip clearance vortex was resolved at the suction side of the blades.

Keywords

Particle Image Velocimetry Rotor Blade Suction Side Turbine Rotor Squealer Cavity 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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Notes

Acknowledgments

The financial support from the Deutsche Forschungsgemeinschaft (project no. Cz55/22-1) is gratefully acknowledged. The investigations were conducted as part of the research program AG Turbo COORETEC. The work was supported by the Bundesministerium für Wirtschaft und Technologie (BMWi) according to a decision of the German Federal Parliament under grant number 0327716V. The authors gratefully acknowledge Rolls-Royce Deutschland and Alstom for their support and permission to publish this paper. The responsibility for the content lies solely with its authors.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Andreas Fischer
    • 1
  • Jörg König
    • 1
  • Jürgen Czarske
    • 1
  • Clemens Rakenius
    • 2
  • Gregor Schmid
    • 2
  • Heinz-Peter Schiffer
    • 2
  1. 1.Laboratory for Measurement and Testing TechniquesTechnische Universität DresdenDresdenGermany
  2. 2.Department of Gas Turbines and Aerospace PropulsionTechnische Universität DarmstadtDarmstadtGermany

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