Flow behavior near an infinite droplet stream

This paper presents an experimental study examining the behavior of a single droplet displaced radially from an infinite droplet stream. The displaced droplet behaves as a tracking particle that responds to the velocity profile generated by the droplet stream. This profile changes with droplet spacing. The measurements show that the velocity field of the infinite stream extends more than 15 droplet diameters from the stream axis, with the largest gradients residing within 5 diameters. The effects of drag and electrostatic forces are quantified to demonstrate that lift forces contribute to the displaced droplets's motion.The monetary support for this work was provided through a NSF Presidential Young and Investigator grant. The authors also recognize the laboratory efforts of Dameon Wood in setting up the charge deflection apparatus.