Liquid motion and internal pressure in electrically stressed insulating liquids

The electrical conductivity of hexane and transformer oil was found to be reduced by filtering the liquid through filters of pore size down to 10 nm, whereas no change in the liquid motion under the applied electric stress could be detected. It is concluded that a part of the measured conductivity is due to the charge carried by particles and that the particles are not the main cause of the liquid motion. Effects of the pressure developed in electrically stressed insulating liquids and of cavitation at the electrodes are discussed. At high fields, liquid jet motion from a point electrode is reported and evidence suggests that the charge in the jet may be carried within a spray of bubbles produced by cavitation at the electrodes.