Enhancement of Evaporation of a Droplet Using EHD Effect : Onset of Instability of Gas-Liquid Interface under Electric Field Applied in a Stepwise Manner

Abstract

An experimental study is conducted to investigate the onset of instability of a liquid surface under an electric field applied in a stepwise manner. The critical voltages and the response times above which the liquid surface becomes unstable are measured under electric fields applied in two different ways. Instability criteria are derived theoretically using a modified Rayleigh-Taylor instability equation for the cases of a perfectly conducting liquid and a perfectly insulating liquid. According to the results of the experiment and theoretical analysis, consideration is made of the mechanism of the onset of EHD (electro-hydrodynamic) instability of the liquid surface having a long electrical relaxation time.