0
research-article

A hydrodynamic study of a propeller turbine during a transient runaway event initiated at the best efficiency point

[+] Author and Article Information
Melissa Fortin

Hydraulic Machines Laboratory, Department of Mechanical Engineering, Laval University, Quebec City, QC, G1V 0A6, Canada
melissa.fortin.2@ulaval.ca

Sébastien Houde

Hydraulic Machines Laboratory, Department of Mechanical Engineering, Laval University, Quebec City, QC, G1V 0A6, Canada
sebastien.houde.6@ulaval.ca

Claire Deschênes

Hydraulic Machines Laboratory, Department of Mechanical Engineering, Laval University, Quebec City, QC, G1V 0A6, Canada
claire.deschenes@gmc.ulaval.ca

1Corresponding author.

ASME doi:10.1115/1.4040232 History: Received January 19, 2018; Revised May 05, 2018

Abstract

This paper presents a hydrodynamic study of a propeller turbine runaway based on flow simulations and measurements results. Runaways are considered one of the most structurally damaging conditions a hydraulic turbine may encounter. This study focuses specifically on the flow dynamics in the runner and draft tube of a model propeller turbine installed on the test stand of the Hydraulic Machines Laboratory of Laval University, Quebec, Canada. The controlled runaway event reproduced on the test stand was part of a larger study into transient flow conditions. Beside global performance parameters, the measurements also featured 31 pressure transducers mounted on two runner blades. Using those measurements results, both as boundary conditions and for validation purposes, unsteady Reynolds-averaged Navier-Stokes (URANS) simulations of the entire turbine were performed. Those simulations featured transient boundary conditions to reproduce discharge and runner speed variations. Using wavelet transforms analysis, the evolution of the dominant pressure fluctuations are tracked in both, the measurements and the simulations. The wavelet analysis revealed the presence of pressure fluctuations with frequencies at a fraction of the runner rotation speed. Numerical results revealed that a vortex structure in the draft tube, similar to a part-load vortex rope, is the cause of those high-pressure fluctuations in the runner. A slight flow separation is observable on the pressure side of the blades but does not alter the flow in the inter-blade channels. Comparisons between experimental and numerical data also outline the limits of the methodology related, among others, with the imposition of strict boundary conditions.

Copyright (c) 2018 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

Discussions

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 Journal Articles
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