Author(s): Oliver Kirschner; Stefan Riedelbauch

Linked Author(s): Stefan Riedelbauch

Keywords: No Keywords

Abstract: In this experimental investigation, the runner forces and torques` fluctuating components are measured on a model pump-turbine for different operating conditions in turbine operation. Two series of measurements are presented. In the QED variation measurement, the explored operating points maintain nearly the same speed factor nED as the best efficiency point (BEP), while the discharge factor QED varies. In the nED variation measurement, the investigated operating points have approximately the same discharge factor QED as the point of best efficiency, while the speed factor nED varies. The results are presented in the rotating and non-rotating frame of reference. It is observed that fluctuations in the region of the optimum have the lowest values. In this region, only higher amplitudes at harmonics of the runner-speed are visible. In both series, the amplitudes of the forces and torques increase in the ranges where the speed factor or the discharge factor deviates by more than approximately 20% from the best efficiency point (BEP).

DOI: https://doi.org/10.1088/1755-1315/1561/1/012026

Year: 2025