The Stereo-PIV investigation of the unsteady flow in the draft tube of a model hydro turbine

Authors

  • Ivan Litvinov "Kutateladze Institute of Thermophysics, Novosibirsk, Russia; Novosibirsk State University, Novosibirsk, Russia"
  • Dmitry Sharaborin "Kutateladze Institute of Thermophysics, Novosibirsk, Russia; Novosibirsk State University, Novosibirsk, Russia"
  • Sergey Shtork "Kutateladze Institute of Thermophysics, Novosibirsk, Russia; Novosibirsk State University, Novosibirsk, Russia"
  • Vladimir Dulin "Kutateladze Institute of Thermophysics, Novosibirsk, Russia; Novosibirsk State University, Novosibirsk, Russia"
  • Sergey Alekseenko "Kutateladze Institute of Thermophysics, Novosibirsk, Russia; Novosibirsk State University, Novosibirsk, Russia"
  • Kilian Oberleithner Technische Universit├Ąt Berlin, Berlin, Germany

DOI:

https://doi.org/10.18409/ispiv.v1i1.102

Keywords:

stereo PIV, pressure sensors, hydroturbine, phase-averaging, POD

Abstract

Varying the generator load of a hydro turbine results in short-term changes in the rotation frequency of the runner, leading inevitably to flow instability and strong flow swirling behind the turbine. This may lead to the formation of unsteady flow regimes featured by vortex instability of the swirling flow behind the runner, known as the precessing vortex core (PVC) Dorfler et al. (2012). This effect causes dangerous periodic pressure pulsations that propagate throughout the water column in the draft tube. The present study reports on stereo PIV measurements of the air flow field inside a transparent draft tube of a model hydro turbine for a wide range of operation conditions. The research is focused on the time-averaged flow properties (mean velocity field and the second-order moments of velocity fluctuations), pressure pulsations and coherent flow structures in the velocity field.

Downloads

Published

2021-08-01

Issue

Section

Other Applications