Abstract：For biodiesel emulsification process in the method of electrostatic atomization in liquid-liquid system,the dispersion equation of charged liquid jet was established. By numerical calculation with Matlab, the effect of jet velocity, charged voltage, viscosity and surface tension of water and biodiesel on the jet instability was obtained. The results show that the increasement of the velocity or the charge voltage of the water jet in water -biodiesel system can lead to the increase of the maximum growth rate of the interface wave and the corresponding optimal wave number. The viscosity of the water impedes the breakup and atomization of the water jet, while the viscosity of the biodiesel contributes to the breakup and ato-mization of the water jet. The smaller the interfacial tension of water-biodiesel, the more favorable it is to the process of electrostatic atomization in liquid-liquid system. Therefore, in the practical application of biodiesel emulsification in the method of liquid-liquid electrostatic atomization, in addition to increasing the jet velocity and the charged voltage, the temperature of water should be increased and the temperature of biodiesel should be reduced as much as possible to obtain fine grained uniform discrete droplets and to get high quality biodiesel emulsified fuel.
