Numerical simulation of salt-water drop motion in an Electric field

In the present study, the effect of the uniform electric field on the hydrodynamic of salt-water drops in crude oil is studied. For this approach, COMSOL Multiphysics software is used, which is based on the finite element method. The obtained results are compared and validated with the available numerical and analytical results and good agreement is observed. The effect of different parameters including the electric Capillary number, the Reynolds number, direction of the electric field, and the relative permittivity of fluid, on the movement of a single drop of saltwater in crude oil under the electric field, is investigated. The results reveal that electric stresses at the interface cause drop deformation and elongation in the direction of the electric field. The magnitude of this deformation increased with increasing the ratio of electric force to surface tension (electric capillary number). Also, the motion process of drop takes longer time in vertical electric field compared with the horizontal electric field in the same condition. Therefore, a uniform external electric field can be used for non-contact controlling of a dropping movement.