Experimental investigation on electrostatic spray of twin-fluid atomization

摘要

A kind of electrostatic atomizer of twin-fluid atomization with combined needle and annular electrode was developed, from which a relative high speed electrostatic spray are obtained. The flow filed of charged droplets from the electrostatic spray under different charging voltage was measured by PIV technique. The characteristics of atomization and motion of droplets of uncharged and charged spray was investigated systemically and analyzed by PIV and PDA systems. The flow field of the twin-fluid jet of electrostatic spray and droplet size distribution is visualized by PIV and PDA measurement technique. The results indicate that the flow field of spray is affected apparently by electrical field. The velocity in the spray center become higher and the flow field around the spray shows a change of fluctuation with the increase of charging voltage. The diameter of spray droplets on the centerline increased when the spray was charged and keep the trend of gradually increase from the center point to the edge of the spray. The spray expanded when it was charged and the spray angle become difficult to define since more particles distributed around the spray core.