Monitoring Cavitation Regime From Pressure and Optical Sensors: Comparing Methods Using Wavelet Decomposition for Signal Processing

A cavitating two-phase flow of water in a pipe with area shrinkage was experimentally investigated, acquiring at high sampling rate pressure signals and images of the cavitating flow-field. The fluctuations of the pressure measurements in the internal orifice and of the intensity level of the images´ pixels were decomposed using the wavelet transform to analyze the frequency distribution of the signals energy with respect to the flow behavior and to highlight the influence of temperature on the phenomena under investigation. It was shown that the energy content at each frequency band of the acquired signals is well related to cavitation flow-field behavior.