At any operating zone in a Hydro turbine, relative motion between the impeller blades and the guide vanes generates pressure fluctuations that propagate through the entire machine. For the weak interactions, time averaged characteristics of machine are not modified and it works in quasi static operating conditions. However, for strong interaction, vibrations, hydraulic noises and even blade cracks could be introduced. In the development of hydroturbines, it is crucial to limit the negative effects of RSI. In the face of this problem, the key issue is to understand the mechanism of the RSI and identify the effective parameters that may increase the pressure fluctuations.
Doctoral student : Alireza Zobeiri
Numerical and experimental investigations are performed to develop further knowledge on rotor-stator interaction in the generating mode of a pump-turbine. Improving the availability and reliability of the hydro turbines is a challenge from a scientific and a technical point of view, which strongly depends on the gathered knowledge of how the complex phenomena in fluid hydrodynamic behavior develop during off design conditions. The mentioned simulations are accomplished at three operating points including a part load and full load operating conditions. The results are compared and analyzed to probe the way of pressure advection and determine the source of perturbation RSI phenomena. The mentioned investigations are performed in the frame work of HYDRODYNA, Eureka Research Project n° 3246.