Study of low-frequency ultrasonic cavitation fields based on spectral analysis technique

A kind of new spectral analysis method for analyzing ultrasonic cavitation fields is brought forward in this paper. This method extracts the line spectrum and the continuous spectrum from the cavitation noise spectrum respectively, then obtains estimations of the energy intensities of different cavitation components such as the stable cavitation and the transient cavitation through corresponding calculations. The method is also applied to investigate low-frequency ultrasonic cavitation fields and is compared with spectral level analysis method. The results show that this method can provide adequate information on the course of the cavitation process, give the delicate analysis on the transient cavitation and the stable cavitation, and help to gain an insight into the nonlinear process of cavitation fields. Moreover, it also shows that the criterion for characterization of cavitation intensity presented by Frohly through studying the high-frequency ultrasonic fields can be used to evaluate the low-frequency ultrasonic fields.