Electrostatic effects on investigation of dispersed droplets in dielectric liquids

Electrostatic atomization of liquids is now considered as a well established technique for creating finely mono-dispersed liquid droplets. One of the techniques in producing stable emulsion is to make finer droplets of dispersed liquids using electrohydrodynamic actuators. This work is to investigate the hydrodynamics of dispersed droplets of water in a continuum dielectric fluid of silicon 100Cst. The effects of flow rate of liquid jet, applied voltage and electrical conductivity of liquids on droplet motion and its deformation were considered. By a nozzle with inner diameter of 1.4 mm water and chloride potassium droplets were generated and were forwarded into the dielectric silicon oil as a base of quiescence medium .In order to produce fine droplets, EHD actuator which produce a high voltage between nozzle and a ring as a ground electrode were used. By this method, a stable water and chloride potassium droplets in oil without any surfactants was produced. It was observed that increasing in flow rate of injection educes the effect of EHD on droplet size decreasing. Droplet Injection from nozzle causes different patterns which have been strongly depended on strength of electric field. In this work, two kinds of flow patterns were considered: dripping mode and spray jet mode. The behaviour of droplets depends on sizes which are completely difference for above mentioned modes. The conductivity of dispersed media is important in dielectric base. For KCL solution with more conductivity than water it is observed the direct effects of this property on diminishing of droplet size

کلیدواژه ها:

Droplet size ، Dielectric liquid media ، Conductivity ، Electrohydrodynimic