Hydropower plays a key role in the actual energy market due to its fast response and regulation capacity. In that way, hydraulic turbines are increasingly demanded to work at off-design conditions, where complex flow patterns and cavitation appear, especially in Francis turbines. The draft tube cavitation surge is a hydraulic phenomenon that appears in Francis turbines below and above its Best ...

The importance of renewable energy sources for the electrical power supply has grown rapidly in the past decades. Their often unpredictable nature however poses a threat to the stability of the existing electric grid. Hydroelectric powerplants play an important role in regulating the integration of renewable energy sources into the network by supplying on-demand load balancing as well as primar...

The present paper demonstrates a proof-of-concept by introducing variable guide vane system in the draft tube of high-head Francis model turbine. aim is to examine hydraulic performance turbine while mitigating pressure pulsations tube. vanes can rotate about an axis up ±45°. mitigation studies were performed at lower- and upper-part loads. was examined all operating ranges within head. There s...