Numerical Analysis of the Deformation of Aqueous Drop Under Uniform Electric Field

This article presents a numerical analysis of the deformation of an aqueous drop in an oil phase under electric field. The configuration of analysis is a sessile aqueous drop located on an electrode. We use the charge simulation method (CSM) to calculate the electric field in the configuration. The drop profile is determined by solving the augmented Young–Laplace equation. The solution is obtained by iteratively adjusting the drop contour and the fictitious charge for the CSM. Experiments were carried out to observe the behavior of an aqueous sessile drop in a parallel electrode system. The comparison between the experimental and numerical results shows a good agreement of the drop profiles for a wide range of the applied electric field. The calculated critical electric field of drop instability is lower than the value from the experiments by 4%. We employ the numerical analysis to clarify the effects of drop size, interfacial tension coefficient, and mass density of the oil phase on the deformation and the critical electric field of the aqueous drop.