When an ultrasonic wave passes through a liquid medium, containing microscopic gas inclusion, it can produce cavitation. At the boundary of a cavitating zone, a voltage appears as a effect of the collapse/rebound cycle of the cavitation bubbles. In this paper we establish a mathematical model of the voltage induced at the boundary of an acoustic cavitation zone, when the liquid was the crude oil. It is compared to that obtained for diesel, in order to prove that the ARIMA process can appropriately describe the fluctuations of generated voltage in different liquids. We also discuss the hypothesis of the relation between the ARIMA parameters and the liquid nature.

PACS numbers: 43.35.Cg