Abstract: This study investigates the unsteady pressure fluctuations in a hydraulic turbine observed during a dangerous case of steep ramping interrupted by an unexpected transition into total load rejection. Although hydraulic ...

Abstract: Previous studies suggested variable speed operation (VSO) of Francis turbines as a measure to improve the efficiency at off-design operating conditions. This is, however, strongly dependent on the hydraulic design and, for ...

Abstract: In Francis turbines, which are normally designed at a reaction ratio of 0.5, the available pressure energy in the fluid is converted into 50% kinetic energy before entering the runner. This causes high acceleration of the ...

Abstract: Control valves, nozzles, and other mechanical flow constricting constructions often introduce highly turbulent flow downstream of vena contracta. When solid particles are present in the fluid stream erosion can occur due ...