Negative Corona discharge from a Viscous Water Droplet

摘要

Negative corona discharge from a water droplet under a dc electric field involves periodic formation of a Taylor cone and ejection of some extent of charge. The periodical motion at the formation of the cone is consistent with resonant vibration of the volume of a tip of the water droplet. To confirm the effect of water viscosity on corona discharge from a water droplet, corona phenomena was investigated by using a grounded tip of capillary electrode to a ring electrode system and by mixing starch sugar with ion exchanged water. A water droplet with a viscosity below 5.7 mPa?s manifests the periodic vibration with corona pulse trains. Water viscosity affects the frequency and the time variation of pulse height in a series of corona pulse trains. This means the motion of the water droplet is strongly influenced by viscosity.