Effect of an entrained air bubble on the acoustics of an ink channel.
Piezo-driven inkjet systems are very sensitive to air entrapment. The entrapped air bubbles grow by rectified diffusion in the ink channel and finally result in nozzle failure. Experimental results on the dynamics of fully grown air bubbles are presented. It is found that the bubble counteracts the pressure buildup necessary for the droplet formation. The channel acoustics and the air bubble dynamics are modeled. For good agreement with the experimental data it is crucial to include the confined geometry into the model: The air bubble acts back on the acoustic field in the channel and thus on its own dynamics. This two-way coupling limits further bubble growth and thus determines the saturation size of the bubble.
Physics of Fluids Group, Faculty of Science and Technology and Burgers Center of Fluid Dynamics, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands.
Roger
R
Jeurissen
Jos
J
de Jong
Hans
H
Reinten
Marc
M
van den Berg
Herman
H
Wijshoff
Michel
M
Versluis
Detlef
D
Lohse
D000162:Acoustics; D000388:Air; D000465:Algorithms; D004058:Diffusion; D007281:Ink; D008433:Mathematics; D045423:Microbubbles; D008962:Models, Theoretical; D009991:Oscillometry; D011312:Pressure