Levich Institute Seminar Announcement, 05/18/2010
Tuesday, 05/18/2010
2:00 PM
Steinman Hall, Room #312
(Chemical Engineering Conference Room)

Professor Osman Basaran
Purdue University
Department of Chemical Engineering

"EHD Jetting and Emission of Charged Drops from Taylor Cones"


ABSTRACT


When subjected to strong electric fields, raindrops in thunderclouds, pendant drops in electrospray mass spectrometry, and planar films form conical tips and emit thin jets from their tips. Theoretical analysis of the temporal development of such electrohydrodynamic (EHD) tip-streaming phenomena has heretofore been elusive given the large disparity in length scales between the macroscopic drops/films and the microscopic jets. Here, simulation and experiment are used to investigate EHD tip-streaming from a liquid film of finite conductivity. In the simulations, the full Taylor-Melcher leaky-dielectric model, which accounts for charge relaxation, is solved to probe the mechanisms of cone formation, jet emission, and breakup of the jet into small drops. Simulations show that tip-streaming does not occur if the liquid is perfectly conducting or perfectly insulating. A scaling law for sizes of micro-(nano-)scale drops produced from the breakup of the thin jets is also developed.

BRIEF ACADEMIC/EMPLOYMENT HISTORY

  • Purdue University, Reilly Professor of Fluid Mechanics, 2/2003
  • Purdue University, Professor, Chemical Engineering, 7/1995 present
  • Oak Ridge National Laboratory, Group Leader and Staff Member, 12/1987 6/1995
  • University of Tennessee, Adjunct Professor (part time), Chemical Engineering, 8/1988 8/1996
  • Air Products and Chemicals, Senior Process/Research Engineer, 4/1984 12/1987

RECENT RESEARCH INTERESTS

Interface rupture and drop breakup in single-fluid and two-fluid flows Electrohydrodynamics and dynamics of charged drops and jets Ink jet printing Dynamics of complex fluids (polymeric and surfactant-laden systems) Capillary switches or double-droplet systems