Ultrasonic drying is a way to use high-frequency vibrations generated by piezoelectric transducers to reduce drying time and energy consumption. This involves capillary wave and cavitation theories. Upon excitation of the liquid droplet, ultrasonic waves are transmitted through the liquid phase, generating capillary waves at the liquid-vapor interface. At high oscillation intensities, the waves become unstable and undergo rupture to form a fine mist. Competing forces of oscillation force and surface tension force determine the particle size and uniformity.
J. Yagoobi, Y. Lee