Breakup of a leaky dielectric droplet in a half-sinusoidal wave electric field

Abstract

In the numerical simulation of droplet breakup under electric field, the meshless method has inherent advantages, however the enforcement of boundary conditions is challenging. Therefore, a coupling method of smoothed particle hydrodynamics(SPH) method and finite volume method(FVM) is proposed to investigate the breakup behavior of leaky dielectric droplet under half-sinusoidal wave electric field. The present numerical method is validated and is well consistent with results in the literature. The effects of electric field strength and droplet viscosity on droplet breakup are mainly discussed, and three different modes of droplet breakup are revealed: conical-conical angle breakup, dumbbell-dimple breakup and cylindrical-non tip breakup. The regions of these three breakup modes are plotted in the breakup phase diagram of electric capillary number and viscosity ratio. The numerical experiments also demonstrate that the droplet breakup mode depends on the velocity field and pressure field of the droplet and the surrounding fluid.