Hydropower is a clean and renewable source of energy which is widely used to generate
electric power and stabilize the power grid. It can respond quickly to any change in demand …

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 …

Abstract Rotating Vortex Rope (RVR) resulting from flow instabilities inside draft tube affects
the hydraulic turbine's efficiency and wear. Among the passive and active RVR mitigation …

Abstract Development of rotating vortex rope (RVR) at part load (PL) operation is a source of
pressure fluctuations in draft tube and power swings, which may lead to runner failure under …

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 …

An experimental investigation of the cavitating turbulent flow in a simplified hydraulic turbine
was carried out to examine flow features in a wide range of speed and discharge conditions …

In hydraulic turbines, either Francis or axial turbines, a high swirling flow is generated at PL
conditions at the inlet of the draft tube resulting in the formation of a rotating vortex rope …

The off-design operation of Francis turbines results in the onset of flow instabilities. These
instabilities lead to severe pressure pulsations, power swings, fatigue damage, and torque …

When a hydro turbine deviates from the best efficiency conditions and carries the partial
load, the helical vortex rope appears in the center of the draft tube. It will cause the unstable …

This paper presents the effect of the conical diffuser angle (θ= 0°, 2°, 4°) on the Precessing
Vortex Core (PVC) induced in confined swirling airflows generated by axial swirlers with two …