Vibration of the horn affects the Rayleigh jet breakup

There have been a number of studies on the Plateau–Rayleigh instability and the influence of the initial jet perturbation on the jet breakup. Our study observed that the threshold lengths of jet breakup varied with the voltage applied to the piezoelectric sheets during the droplet generation for extreme-ultraviolet (EUV) source and wafer cleaning. Combining acoustics and fluid mechanics, we investigated the process and mechanism to interpret the impact of the horn vibration on the jet breakup. The whole process of the vibration delivery from the horn to the jet was summarized: generated by the horn, the vibration transmits into the water, spreads in the chamber, stimulates the jet through the orifice, and grows continuously, causing the jet breakup. In order to validate the analysis, a series of experiments were carried out and compared with the theoretical predictions. The vibration mode and amplitude of the horn were determined by the scanning laser vibrometer. With the hydrophone detection, the distribution of the vibration in the axial direction at the nozzle outlet was studied, and the delivery of the vibration in the chamber was discussed. To verify the influence of the vibration in the chamber on the jet breakup, we compared the results of jet breakup under different sound pressures. Besides, a theoretical model of the jet breakup length versus the piezoelectric sheet voltage was proposed. The study of the whole process provides guidance for changing the jet breakup length by adjusting the voltage and helps to investigate other parameters of the jet breakup process.