On-aim generation of monodisperse droplets from piezoelectric pulsation-driven glass nozzles

Abstract

Piezoelectric pulsation-driven glass nozzles are capable of generating monodisperse droplets through liquid jet breakup. Due to the lack of fundamental understanding of this process, how to ensure uniform droplet generation with a specified size for liquids with specific rheological properties remains unknown. In this work, the complete atomization process including phenomena in and outside of the nozzle has been described by a new multi-physics model, where the expensive in-nozzle simulation can be rigorously replaced by a semi-empirical relationship. This computationally efficient model allowed us to systematically and quantitatively explore the influence of different material and operating parameters on jet breakup. It was found unintuitively that the surface tension has negligible influence on droplet size and its distribution. The droplet size can be independent of the nozzle radius under the condition of a constant inflow rate. Moreover, a detailed guideline was established to achieve on-aim size control of the atomized droplets.