Atomization Threshold in a Layer of Distilled Water

Ultrasonic atomization is a process receiving high attention, from the first report about the phenomenon in the thirties, Wood1 until nowadays. Ultrasonic atomization has been treated by Sorokin2, Eisenmenger3, and Pholman4, in these works both theoretical and experimental of phenomena were faced and equations for the critical atomization amplitude were obtained. In this paper, an experimental research for capillary waves is presented. The work faced aspects of ultrasonic atomization as the threshold of atomization for different frequencies near the transition between gravity to capillary waves, also the existence of minimum mass for the atomization of a sessile distilled water droplet on a metallic vibrating surface was studied. Our results show the existence of an atomization mass threshold in both senses: For excess and defect, in addition, the atomization thresholds for different frequencies in a frequency range from 30 to 200 Hz were obtained. As it can be expected, the thresholds present a strong dependence on frequency. With our actual experimental set-up, we could not detect with accuracy enough differences in the atomization threshold for a sessile droplet on different vibrating substrates. © 2018 Acoustical Society of America.