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Title: A numerical study of secondary flows in a 1.5 stage axial turbine guiding the design of a non-axisymmetric hub
Authors: Obaida, Hayder M. B.
Kadhim, Hakim T. K.
Rona, Aldo
Leschke, Katrin
Gostelow, J. Paul
First Published: 25-Jun-2017
Presented at: ASME Turbo Expo 2017, Turbomachinery Technical Conference and Exposition GT 2017, Charlotte, NC, USA
Start Date: 25-Jun-2017
End Date: 30-Jun-2017
Publisher: American Society of Mechanical Engineers ASME
Citation: Proceedings of ASME Turbo Expo 2017, Turbomachinery Technical Conference and Exposition GT 2017, 2017, pp. 1-12
Abstract: 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.
DOI Link: 10.1115/GT2017-65251
ISBN: 978-0-7918-5079-4
Embargo on file until: 1-Jan-10000
Version: Post-print
Status: Peer-reviewed
Type: Conference Paper
Rights: Copyright © 2017, American Society of Mechanical Engineers ASME. All rights reserved.
Description: 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.
Appears in Collections:Conference Papers & Presentations, Dept. of Engineering

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