Research on an acoustic judgment method for the incipient cavitation of model hydraulic machinery runner blades

The cavitation phenomenon is an important factor affecting the safe and stable operation of hydraulic machinery units. units can lead to increased vibration, reduced efficiency, erosion blades. Therefore, a method needed determine incipient runner This study initiated from acoustic characteristics bubbles generated by model turbines radiated sound energy during cavitation. noise are studied. After qualitative analysis high- low-frequency distribution patterns signals before after cavitation, mathematical time-frequency these proposed using method. feature information extracted used judge occurrence in turbine Based on this method, online monitoring system constructed, comparative tests carried out pump Francis turbine. It found that results for judgment highly consistent with those traditional methods.