Small Bubble Formation by Using Strong Nonuniform Electric Field

An experimental study on a small bubble formation was carried out to examine the effect of electric field on it. The nitrogen bubble in insulating liquids was divided easily into small ones by means of a strong nonuniform electric field. It has been recognized that a strong electrical pressure arises at the tip of the capillary electrode where almost all the line of electric force concentrates and that it increases with increasing applied voltage, while bubble size decreases markedly depending on the electrical properties of the liquids. The efficiency of the small bubble formation also depends on the electrical properties of the liquids, and it reaches a few percent for good insulating liquids. An additional experiment was performed to observe the generation of an electrohydrodynamic (EHD) flow of liquid and to discuss its contribution to the small bubble formation.