Over the past decade, the use of conventional one-dimensional numerical-simulation
methods has been demonstrated to be inadequate in terms of their usefulness in …

Operational flexibility of hydraulic turbines is impeded by the vortex breakdown
phenomenon. The phenomenon, a consequence of instability in vortical flows in general …

Francis turbine working at off-design operating condition experiences high swirling flow at
the runner outlet. In the present study, a high head model Francis turbine was …

Abstract Rotating Vortex Rope (RVR) has been a matter of focus for years due to the major
effects on hydraulic turbine's efficiency. The exact procedure of RVR formation is still vague …

Owing to the need for power grid peak regulation and frequency regulation, the pumped
storage unit has to undergo frequent working condition conversion, and the pump turbine …

The rotating vortex rope, which can be decomposed in the rotating and the plunging modes,
is the origin of pressure fluctuations in the draft tube cone when hydraulic turbines operate at …

Francis turbines within hydropower plants are required to operate under off-design
conditions to meet the grid demand and ensure stability. In line with this, part-load conditions …

Hydraulic turbines are increasingly responsible for regulating the electric grid, due to the
rapid growth of the intermittent renewable energy resources. This involves a large increase …

The transient characteristics associated with the machine load rejection process are
investigated due to its close relationship with hydraulic facilities' safety in low-head tubular …

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