Unshrouded rotor tip clearance effects in expander cycle turbines
Author
Summary, in English
A series of subsequent simulations is thus used to judge the impact of varied blade/stage design parameters.
Two turbine layouts are defined for identical operating conditions and shaft power. The flow in the unshrouded rotor blade row is analyzed for the influence of varying tip clearance size and the dependency on stage velocity triangles. – Known correlations for tip clearance losses (typically used in mean line predictions) are used, though the blade row geometry considered is beyond the limits the correlations are intended for. The absolute loss level found in CFD simulations differs significantly from what is expected when using loss correlations. Still the variation with tip gap size is predicted well by some of the investigated models. As dependency of tip clearance losses on stage velocity triangles is considered, none of the tested correlations gives results consistent with the numerical simulations. The use of standard correlations ‘beyond the limits’ is thus considered to introduce high uncertainty.
Due to the good consistency between LDA and numerical results, the conclusions are considered to be valid for stage designs similar to the ones analyzed.
Department/s
Publishing year
2002
Language
English
Publication/Series
Proceedings of the ASME Turbo Expo
Document type
Conference paper
Publisher
American Society Of Mechanical Engineers (ASME)
Topic
- Energy Engineering
Keywords
- loss correlation
- tip clearance
- CFD
- LDA
Conference name
2002 ASME Turbo Expo: Land, Sea and Air
Conference date
0001-01-02
Conference place
Netherlands
Status
Published
ISBN/ISSN/Other
- GT2002-30338