In this study,the breakup of a melt jet into a viscous medium is investigated in the presence of an intense electric field.Fragmentation of the melt jet occurs due to both hydrodynamic and electrohydrodynamic (EHD) forces within two kinds of silicone oil of different viscosities.The size and shape characteristics of the produced particles have been studied using SEM images,and the particle size distributions were found to exhibit considerable variations when a voltage was applied and when both the viscosity and temperature of the base fluid were changed.The morphologies of the particles were also affected by the same parameters.For instance,by applying EHD force,significant enhancements in size reduction and increased roundness of the particles occurred.The breakup process of the melt jet was found to be dominant by hydrodynamic or electrohydrodynamic instabilities,depending on the situation.Governing mechanisms (instability) in the cases of pure hydrodynamic and electrohydrodynamic fragmentations are discussed.