Acoustic Emission-Based Monitoring of Vibration-Induced Cavitation in Thin Liquid Layer

Vibration-induced cavitation is a phenomenon that exists in a variety of fluid–solid coupled industrial scenarios. High frequency excitation, such as ultrasound, is required to trigger cavitation in large volume flow fields, whereas in thin liquid layers, cavitation can be triggered by low frequency excitation. To investigate the relationship between cavitation behavior and acoustic emission response, a thin liquid layer vibration-induced cavitation test system has been developed in this paper. The cavitation state is determined visually by high-speed photography, providing a basis for the identification and extraction of cavitation-related features in acoustic emission signals. The results show that when cavitation occurs, the occurrence of cavitation causes the AE signal to add a frequency component in the range of 200–250 kHz, the amplitude of which increases as the degree of cavitation increases. The study provides a practical reference for future research on the monitoring of vibrational cavitation.