Experimental investigation of cavitation-induced noise and vibration in a centrifugal pump

Cavitation has become a serious concern threatening operational stability as the need for high-speed machinery has grown. In this study, noise (sound pressure level) and vibrations (structural) were measured in a radial flow centrifugal pump for design and off-design conditions under cavitation. Because the structure of a particular noise/vibration spectrum (as well as its total level) is affected by the operating conditions and stage of cavitation within the pump, a detailed analysis of the noise/vibration spectra during the pumping process was carried out to detect the cavitation phenomenon's progression. We aim to identify the association between noise/vibration and the corresponding net positive suction head value at different flow rates. The results showed that the cavitation structure affects the vibration/noise behavior of the pump. Moreover, total noise level measurements at partial flow rates cannot be used to diagnose full cavitation breakdown, whereas total noise level measurements can be used to detect cavitation intensity at higher flow rates than the optimum operating point.