|
Abstract
|
In this study, the behavior of dielectric liquid jet in the presence of electric field was analyzed and the effects of electrode
geometry and electric field direction on surface wave frequency, jet breakup, and produced droplet characteristics were
investigated. When a dielectric liquid jet flows through an electric field, three types of electric forces can be imposed on the
flow field: electrophoretic, dielectrophoretic, and electrostriction forces. Flow of liquid jet in gaseous surrounding is affected
by electrophoretic and dielectrophoretic forces. Considering the direction of electrophoretic force, applying the electric
field in the direction of jet flow thickens the jet by decelerating the flow; nevertheless, inverse field increases the diameter
of jet by accumulation of liquid in the downstream region of electrodes. Dielectrophoretic force does not depend on field
direction and always increases the diameter of liquid jet. Results showed that breakup length is shortened by electric field
and applying a 6 kV electric potential difference can reduce the upper limit of breakup length by 27% in comparison with
non-electrified case. Furthermore, the electric field increases the production of round droplets and decreases the number
of irregular and sharp-edged droplets. Increase in electric field strength usually leads to reduction in droplet size. Besides,
parallel–triangular electrodes in direct field and star–triangular electrodes in inverse field are more effective in the production
of round droplets. Although smallest droplets are produced using star–triangular arrangement, parallel–triangular electrodes
can produce droplets with more homogeneity in size distribution.
|