Highly-focused liquid jets induced by an impulsive force : viscous jets, high-speed jets, and effects of cavitation
Orateur : Yoshiyuki Tagawa
Tokyo University of Agriculture and Technology
Abstract : A liquid jet is of great importance for various important applications such as ink-jet printers and needle-free injection devices. The development of methods for generating highly-viscous microjets and high-speed jets is expected to open new doors for next-generation technologies. In this presentation we introduce a novel system for generating a highly-viscous microjet with up to 500 cSt. The structure of the device is quite simple as described below : We produce a liquid jet inside a wettable-thin tube that is partially inserted in a liquid bath. We keep the gas-liquid interface inside the tube much deeper than that outside of the tube. We then add an impulsive force at the bottom of the liquid container. The addition of an impulsive force results in the significant acceleration of the liquid inside the tube. This simple yet innovative setup enables us to generate highly-viscous jets. We lead a physical model based on a pressure impulse approach and investigate effects of cavitation on the jets. This jet induced by an impulsive force can be also generated by an illumination of laser pulse, resulting in supersonic microjets with velocity up to 850 m/s. We believe that the development of these systems is a starting point for next-generation technologies such as highly-viscous ink-jet printers including printed electronics and 3D printers, and needle-free injection devices for low-invasive medical treatments.
Date et lieu : le Vendredi 22 Septembre à 11h, salle 255, IUSTI