Numerical Simulation of Drop Deformation and Breakup in an Electric Field

Liquid drop suspension in another fluid occurs in many natural processes. Applying electric field has shown a promising outlook for the control of motion, deformation, breakup and guidance of the drops. In this study, the dynamic response of a liquid drop suspended in another fluid across two conducting electrodes held at different electrical potentials has been simulated. In this regard, the effects of electric potential, electrical conductivity and relative permittivity have been studied. According to results, an increase in electric potential and conductivity leads to increasing trend in drop deformation whereas this trend converts into an ascending-descending pattern due to increase in electrical permittivity. An insight into the flow patterns inside and outside the drop shows that the positioning of a liquid drop in an external electric field in addition to drop polarization results in an electric field induced within the drop which causes the creation of vortices inside the drop. Magnitude of electrical conductivity and permittivity factors compared to each other apparently affect the accumulation area of electrical charges on the drop surface which in turn determines the circulating direction of vortices within the drop. Increasing electric field intensity due to an increase in electrical potential or change in magnitude of other physical properties would fortify the electric charge on the drop surface escalating drop deformation towards drop breakup. In this condition, the electrical polarization in addition to drop prolation causes jet exit from which a continuous line of droplets is emerged until the total dissipation of the drop.