One of the most important milestones in history hydropower is invention Kaplan turbine. It a machine stemming from Francis turbine, which Viktor was originally trying to improve. However, it gradually developed into creation completely new solution an impeller with axial flow rate and adjustable blades. The first patent relating dates 1913. Shortly afterwards, turbine became widely used type de...

Since the birth of the first prototype of the modern reaction turbine, cavitation as conjectured by Euler in 1754 always presents as a challenge. Following his theory, the evolution of modern reaction (Francis and Kaplan) turbines has been completed by adding the final piece of the element 'draft-tube' that enables turbines to explore water energy at efficiencies of almost 100%. However, during...

Hydraulic turbines are usually operating at high efficiencies around 90%. It is possible to increase the efficiency by preventing flow characteristics such as failure, cavitation and vortex rope in draft tube. In some cases, partial loads or overloads, pressure pulsations would occur These undesired events damage components of turbine that also causes decrease. To eliminate these artifacts, it ...

Acoustic resonances in Francis turbines often define undesirable limitations to their operating ranges at high load. The knowledge of the mechanisms governing the onset and the sustenance of these instabilities in the swirling flow leaving the runner is essential for the development of a reliable hydroacoustic model for the prediction of system stability. The present work seeks to study experim...

Experimental tests in prototype are necessary to understand the dynamic behaviour of the machine during different operating points. Hydraulic phenomena as well as its effect on the structure need to be studied in order to avoid instabilities during operation and to extend the lifetime of the different components. For this purpose, a complete experimental study of a large Francis turbine prototy...