Numerical simulation of electrohydrodynamics of a compound drop based on the ternary phase field method.

Analytical and numerical methods are often used to study the behavior of multiphase fluid under electric field. Compared with analytical methods, numerical methods can simulate the real physical phenomenon of multiphase fluid dynamics in a large deformation range. The finite element method is mainly applied in two-phase fluid currently, although it can be used to analyze the small and large deformation of multiphase fluid under electric field. This article attempts to develop a finite element model of a concentric compound drop immersed in continuous medium under electric field based on the ternary phase field method and simulate the electrohydrodynamics of the compound drop whose core phase, shell phase, and continuous phase are different. The small deformation simulation results of the compound drop under weak electric field are compared with the analytical results of previous researchers from the three aspects, namely, deformation, free charge distribution, and flow pattern. This model is proved to be effective under certain conditions. Based on this premise, the large deformation and breakup of the compound drop under high electric field are further simulated to investigate the mechanism of compound drop breakup preliminarily.