Abstract: Onboard experiments were carried out when the waterjet pumps are working on the conditions of none cavitation zone, cavitation zone Ⅰand cavitation zone Ⅱ, acoustic and vibration signals were acquired respectively by hydrophones mounted in the inspection holes and acceleration transducers mounted on the case of the waterjet pumps. It showed that both of the second derivatives of the acoustic and vibration signals have notable differences before and after cavitation, and visible peak values appear in 8-25 kHz of acoustic signal and 3-12 kHz of vibration signal after cavitation. Cavitation feature sets were constituted based on the peak series of the second derivatives for features combined classification. The results show that the three types signals can be distinguished well by features combined classification, and the effect of multi-sensors features combined classification is better than that of single-sensor, especially the effect of multi-sensors features combined classification based on high order derivative  is more perfect.

Key words: waterjet pump, cavitation, feature sets, combined, classification