Abstract：The deionized water was used as discrete phase liquid with biodiesel as continuous phase liquid. According to the interface stress balance, the dispersion equation of discrete phase liquid under the action of needle plate electrode was established, and the characteristics of the interface wave dominating the breakup of discrete phase liquid were analyzed. The microhighspeed camera technology was used to visualize the interface morphology of charged deionized water in biodiesel to obtain the breakup mode and formation mechanism of the discrete phase liquid. The results show that the breakup modes of deionized water in biodiesel can be divided into drop mode, swing drop mode and coneswing jet mode. The observation results of the interface wave characteristics in different modes indicate that in the drop mode, only the axisymmetric wave exists on the interface, while in the swing drop mode and the coneswing jet mode, the axisymmetric wave coexists with the nonaxisymmetric wave. With the increasing of charging voltage, the optimal wave number of the axisymmetric wave and the nonaxisymmetric wave is increased. The optimal wave number of the axisymmetric wave is larger than that of the nonaxisymmetric wave, but its growth rate is slower than that of the nonaxisymmetric wave.
