Experimental Measurement of Cavitation-Induced Vibration Characteristics in a Multi-Stage Centrifugal Pump

抄録

To examine the effect of cavitation on the vibration of a multi-stage pump, a five-stage diffuser centrifugal pump was selected to test the vibration characteristics under non-cavitation and cavitation conditions. Vibrations were monitored at six points (V1–V6). Results show that when cavitation occurs, the vibration characteristic frequencies of the six measuring points obviously increase, for 1.0Q_d (the design flow rate). The gap in the vibration velocity amplitude between the higher axial frequency harmonics and the main frequency becomes smaller, and the cavitation-induced vibration excitation is very obvious in all directions. When the flow rate is 0.8Q_d, peak values at the main vibration frequencies of the measuring points V1, V2 and V4 increase compared to those at 1.0Q_d. Vibration intensities when the flow rate is 1.2Q_d are larger than at 0.8Q_d, and vibration intensities at 1.0Q_d are the lowest of the three. At 0.8Q_d and 1.2Q_d, the maximum vibration intensities of the pump are 2.01 mm/s and 2.47 mm/s respectively, which is an increase of 87.85% and 111.11%, respectively.