Experimental testing on cavitation vibration and noise of centrifugal pumps under off-design conditions

Based on virtual instrument data acquisition system and pump product testing system, cavitation induced vibration and noise testing system was established in the centrifugal pump closed experimental rig, and the synchronous acquisition of pump performance parameters and cavitation induced vibration and noise signal were realized. With a single grade end suction pump as research model, whose vibration and noise signal at design and off-design conditions under different net positive suction head were measured and processed, the curves of vibration acceleration and noise level versus different net positive suction head were obtained. Experimental results showed that: as the cavitation intensified, vibration acceleration and noise stabilized at first and then increased apparently, which could be used to decide the inception net positive suction head; The vibration strength of pump volute was higher than that of other measure points. In addition to the complicated changing regularity of axial vibration, the vibration of other measure points augmented with the increase of flow