The onset of electrohydrodynamic motion in non-polar liquids

Experiments were conducted to investigate the onset of liquid motion, and hence electroconvection, with the application of step voltage. It is necessary to distinguish between pure conduction (no liquid motion) and convection-assisted conduction (enhanced by the liquid motion). To separate these two mechanisms, experiments were carried out using optical and electrical methods, and the delay time necessary for the liquid motion, transit time, and the apparent velocity of charge carriers were measured. Studies based on optical measurements indicate the delay time necessary for the onset of electrohydrodynamic instability. The transient current curve does not show any discontinuity in current with the instability occurrence. Comparison of ionic velocity with apparent velocity shows that the liquid is dependent more on particulate contamination than on ions