This review addresses the current state of research into active control and suppression of
vortex rope in hydroturbines under off-design operating conditions. Only active control …

Hydropower plants provide an asset over other renewables of production flexibility. Away
from the turbine design point; detrimental off-load instabilities may compromise the power …

This work is focused on reduction of swirling in cases from hydraulic machinery and, thus,
mitigation of instabilities associated with swirling flow. We study this problem analytically …

We report on the experimental study of a precessing vortex core (PVC) in an air model of a
Francis turbine. The focus is placed on the modal decomposition of the PVC that occurs in …

The implementation of hydropower to stabilize electrical grids dictates more frequent off-
design operations of these renewable energy resources. Flow instabilities under such …

The part load operation of a Francis turbine generally develops a rotating vortex rope (RVR)
in the draft tube, generating flow instabilities and pressure pulsations. The present work …

The present paper investigates the rotating vortex rope (RVR) mitigation on an axial turbine
model by the radial protrusion of four cylindrical rods into the draft tube. RVR mitigation is of …

To understand the hydraulic vibration characteristics in a traditional hydropower system and
identify possible exciting sources that may induce serious hydraulic vibrations in the flow …

The global demand for electricity generation has been increasing over the recent decades
and is expected to grow steadily. Therefore, activating new energy sources to improve the …

An experimental investigation of frequential protrusion of four solid rods into the draft tube of
a propeller turbine operating under partial discharge has been undertaken. The …