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In this study deformation of a falling drop which is surrounded by another liquid is modeled analytically and numerically. The drop is influenced by an external electric field which is applied uniformly on the side walls of the domain. An open-source volume-of-fluid solver, Gerris with dynamic adaptive grid refinement has been used for numerically modeling the three-dimensional deformation of a falling droplet. Analytical solutions of drop's deformation are presented in detail and then the outcomes are compared with numerical results. The numerical results are presented for various values of density ratios and electrical conductivity and permittivity. The comparison of the results shows a great agreement between the analytical solutions and the direct numerical simulation (DNS) results. [ABSTRACT FROM AUTHOR]

Physical properties and especially the size of drops are important parameters in many industrial and medical applications. High voltage electric field is one of the effective means to control the final size of drops during the fabrication process which could greatly influence the final size of the product. Therefore a detailed study of electric field effect on a liquid drop is very important. In this work deformation and fragmentation of a falling droplet under gravity and electric force have been studied numerically. Electric force is used as an effective external controlling mechanism to influence the deformation of a drop. The three-dimensional deformation of a falling droplet is studied numerically using the open-source volume-of-fluid solver, Gerris. The numerical results are compared with previous analytical, experimental and numerical data and great agreements between the results are obtained. The results are presented for broad range of Bond numbers ( Bo ) from low Bond number (drop with small deformation) to large Bond number (drop breakup and fragmentation). The results revealed that the electric field can be used as a powerful controlling tool in delaying and expediting the falling drop breakup process. The results also showed that falling drop deforms severely by increasing Bo number which leads to the breakup and fragmentation compared to the cases of low Bo number in which the drop deforms mildly without breakup. [ABSTRACT FROM AUTHOR]