Piezoelectric Ultrasonic Transducer for Permeabilization of Organic Materials

The natural oil extraction process can be performed through various methods, one of which employs ultrasonic (US)–induced microcavitation to enhance product quality while reducing the extraction time. This is achieved by means of a piezoelectric (PZE) US transducer, operated within a frequency range determined by the properties of the raw botanical material (e.g., lavender flowers, mint leaves). Additional components are employed to enhance and focus the US waves. This paper analyses the optimal structural design of a bidimensional axisymmetric PZE US transducer. The device has a quadmorph configuration of the PZE layers, and the numerical simulations aim to determine the optimal design while maintaining a constant PZE volume. The analysis focuses on evaluating the eigenfrequencies and resonant frequencies to identify the most efficient configuration. For two best designs, the working vessel is added, and the Navier-Stokes flow equation is solved.