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A numerical study of secondary flows in a 1.5 stage axial turbine guiding the design of a non-axisymmetric hub

conference contribution
posted on 15.06.2017, 10:46 by Hayder M. B. Obaida, Hakim T. K. Kadhim, Aldo Rona, Katrin Leschke, J. Paul Gostelow
The performance of axial flow turbines is affected by losses from secondary flows that result in entropy generation. Reducing these secondary flow losses improves the turbine performance. This paper investigates the effect of applying a non-axisymmetric contour to the hub of a representative one-and-half stage axial turbine on the turbine performance. An analytical end-wall hub surface definition with a guide groove is used to direct the pressure side branch of the horseshoe vortex away from the blade suction side, so to retard its interaction with the suction side secondary flow and thus decrease the losses. This groove design is a development of the concept outlined in Obaida et al. (2016). A baseline three-dimensional steady RANS k-ω SST model, with axisymmetric walls, is validated against reference experimental measurements from a one-and-half stage turbine at the Institute of Jet Propulsion and Turbomachinery at RWTH Aachen, Germany. The CFD predictions of the non-axisymmetric hub with the guide groove show a decrease in the total pressure loss coefficient. The design work-flow is generated using the Alstom Process and Optimisation Workbench (APOW), which sensibly reduced the designer workload. The implementation of the guide groove has excellent portability to the turbomachinery industry and this makes this method promising for delivering the UK energy agenda through more efficient power turbines.

History

Citation

Proceedings of ASME Turbo Expo 2017, Turbomachinery Technical Conference and Exposition GT 2017, 2017, pp. 1-12

Author affiliation

/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Engineering

Source

ASME Turbo Expo 2017, Turbomachinery Technical Conference and Exposition GT 2017, Charlotte, NC, USA

Version

AM (Accepted Manuscript)

Published in

Proceedings of ASME Turbo Expo 2017

Publisher

American Society of Mechanical Engineers ASME

isbn

978-0-7918-5079-4

Acceptance date

03/03/2017

Copyright date

2017

Publisher version

http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2649670

Notes

The file associated with this record is under a permanent embargo in accordance with the publisher's policy. The full text may be available through the publisher links provided above.

Temporal coverage: start date

25/06/2017

Temporal coverage: end date

30/06/2017

Language

en