Woodruff School of Mechanical Engineering

Mechanical Engineering Seminar


Highly focused liquid jets induced by an impulsive force: Viscous jets and high-speed jets


Prof. Yoshiyuki Tagawa


Tokyo University of Agriculture and Technology, Department of Mechanical Systems Engineering


Tuesday, January 31, 2017 at 11:15:00 AM


MRDC Building, Room 4211


Minami Yoda


Liquid jets are of great importance in various applications such as ink-jet printers and needle-free injection devices. The development of methods for generating highly viscous microjets and high-speed jets should open new doors for next-generation technologies. In this presentation, we introduce a novel system for generating microjets of liquids with viscosities up to 500 cSt. The structure of the device is quite simple as described below: A liquid jet is produced inside a thin tube partially submerged in a liquid bath where the gas-liquid interface inside the tube is much deeper than that outside of the tube. An impulsive force is then imposed at the bottom of the liquid container, creating a large acceleration in the liquid inside the tube. This simple novel setup enables us to generate highly viscous jets. We have developed a physical model based on a pressure-impulse approach. This jet induced by an impulsive force can be also generated instead by a laser pulse, resulting in supersonic microjets with speeds up to 850 m/s. The development of such systems is a starting point for novel technologies such as highly viscous ink-jet printers for printed electronics and 3D printers, and needle-free injection devices in medicine.


Yoshiyuki Tagawa did his undergraduate and graduate studies at The University of Tokyo in Japan. He was a Japan Society for the Promotion of Science Research Fellow at The University of Tokyo and a postdoctoral fellow at the University of Twente in the Netherlands. Dr. Tagawa is currently Associate Professor in the Department of Mechanical Systems Engineering at the Tokyo University of Agriculture and Technology. He received the Japan Society of Fluid Mechanics Award for Distinguished Young Researcher in Fluid Mechanics in 2015 and the Japan Society of Mechanical Engineers Young Engineers Award in 2014. Dr. Tagawa is a Fellow of the Japanese Society for Multiphase Flow.


Refreshments will be served.