Procedure for predicting part load resonance in Francis turbine hydropower units based on swirl number and local cavitation coefficient similitude

João Gomes Pereira*, Arthur Favrel, Loïc Andolfatto, Christian Landry, Sebastian Alligné, Christophe Nicolet, François Avellan

*この研究の対応する著者

研究成果: Article査読

13 被引用数 (Scopus)

抄録

Francis turbines operating at part load conditions develop a cavitation precessing vortex known as a vortex rope in the draft tube cone below the runner outlet. At part load conditions, this vortex precession acts as an excitation source inducing pressure pulsations in the whole hydraulic system at the vortex precession frequency. Simultaneously, the lower pressure levels in the vortex core can lead to cavitation development, increasing the local flow compliance and reducing drastically the pressure wave speed. As a result, the eigenfrequencies of the hydraulic circuit are lowered and may match the vortex rope excitation frequency, leading to undesired resonance conditions. This paper presents a procedure to predict this type of resonance phenomenon in turbine prototypes by performing reduced scale physical turbine model measurements and eigenvalue calculations with linearized system matrices. This new procedure requires the transposition of hydroacoustic parameters from the reduced scale physical model to the prototype scale based on the swirl number and the local cavitation coefficient similarity. The procedure is validated by measurements performed on a turbine prototype featuring a peak of power swings and pressure pulsations in the predicted operating conditions.

本文言語English
ページ(範囲)84-101
ページ数18
ジャーナルMechanical Systems and Signal Processing
132
DOI
出版ステータスPublished - 2019 10月 1

ASJC Scopus subject areas

  • 制御およびシステム工学
  • 信号処理
  • 土木構造工学
  • 航空宇宙工学
  • 機械工学
  • コンピュータ サイエンスの応用

フィンガープリント

「Procedure for predicting part load resonance in Francis turbine hydropower units based on swirl number and local cavitation coefficient similitude」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル