Abstract
The aim of this study is to gain a detailed understanding of the behavior of a liquid drop in AC electric fields at finite Reynolds number. A front-tracking/finite difference method, in conjunction with Taylor–Melcher leaky dielectric model, is used to solve the governing electrohydrodynamic equations. The evolution of the flow field and the drop deformation are studied for three representative fluid systems, corresponding to the three regions of the deformation–circulation map. It is shown that for the range of the physical parameters used here, the relaxation time during which the drop settles to its quasi-steady-state deformation is essentially the same as that predicted by the creeping flow solution. Furthermore, the mean (time-independent) deformation is well represented by its steady-state deformation in the corresponding DC field in a root-mean-square sense. The evolution of the flow field shows formation of closed vortices that cross the drop surface and move toward the ambient fluid or the drop, in line with the motion of the drop surface. The evolution of the kinetic energy of the flow field with time is investigated, and the correlations between the minimum and the maximum kinetic energy and the state of the drop deformation are explored.
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Esmaeeli, A., Halim, M.A. Electrohydrodynamics of a liquid drop in AC electric fields. Acta Mech 229, 3943–3962 (2018). https://doi.org/10.1007/s00707-018-2211-6
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DOI: https://doi.org/10.1007/s00707-018-2211-6