Za. Huneiti et al., HARMONIC SPRAYING OF CONDUCTING LIQUIDS EMPLOYING AC-DC ELECTRIC-FIELDS, IEEE transactions on industry applications, 34(2), 1998, pp. 279-285
This paper reports the results of the work tarried out to investigate
the breakup process of charged conducting liquid jet under the influen
ce of an ac field superimposed onto a de field. The main aim of this p
aper is to optimize the spraying parameters and to generate uniform dr
oplets of highly conducting liquid in a controlled fashion by varying
the strength and the frequency of the applied ac field, The electric f
ield at the tip of a blunt needle facing a ground electrode was examin
ed using a finite-element modeling technique, Three types of ground el
ectrode configurations were investigated, A mathematical model for the
electrostatic force on the leading edge of the droplet as a function
of the liquid flowrate, the applied voltage, and distance between the
capillary tip and the ground electrode has been developed, The breakup
and droplet formation processes were investigated using a telemicrosc
opic lens and charge-coupled device (CCD) camera, The video data was p
rocessed using frame grabber software installed on a PC, The digital i
mages were then analyzed utilizing image analysis software to give inf
ormation on the breakup process and the size of droplets. A frequency
range was identified where the formation of the droplets was synchroni
zed with the applied ac field frequency. The effects of liquid flowrat
e on the synchronous bands were examined, The experimental results sho
wed the dependency of the droplets size and the emission frequency on
the applied ac frequency.