Measurement and interpretation of cavitation noise in a hybrid hydrodynamic cavitating device

Abstract

In the recent past, a number of new methods of utilizing hydrodynamic cavitation to create more intense and energy efficient liquid processes have come into existence. However, it is technically challenging to characterize these processes either quantitatively or qualitatively (Patil NM, M. chemical engineering Thesis submitted to Mumbai University, India, 2001). In this work, a hybrid device producing more energy intensive cavitation has been described, which has a blade positioned in the back pressure zone (downstream side of the orifice plate). This method of cavitation production route has been quantitatively described in the form of hydrophone measured pressure signals. Fast Fourier Transform analysis (FFT) analysis has been applied to the signal obtained at various positions of the blade, and at different inlet and outlet (back) pressures. Qualitatively analysis in terms of cavity size distribution and the total number of cavitational bubbles has been conducted, using a slightly modified technique of inverse FFT reconstruction procedure originally developed by Avvaru and Pandit to model cavity size distribution.