Migration of a Leaky-Dielectric Droplet in the Fringe Electric Fields of Parallel Plate Capacitors

Abstract

Abstract This work numerically studies the dynamics of a droplet, uncharged and freely suspended in an immiscible fluid, driven to move by the fringe electric field generated by parallel plate capacitors. Both the droplet and the suspending fluid are considered as leaky dielectrics. The deformation and migration of the droplet through the fringe electric field into or away from the parallel plate capacitors is our focus. A three-dimensional spectral boundary element method for interfacial dynamics in electrical fields is modified and adopted for the current study. The influences of the material properties of the pair of immiscible fluids including the viscosity ratio, surface tension, conductivity, and permittivity on the direction and velocity of the droplet migration will be investigated. The effects of operational and design parameters on droplet motion, including the electrical field strength and the parallel plates’ gap width will be explored as well. In this preliminary study the numerical method will then be applied to investigate the entrapment processes of fine CO2 bubbles in two-dimensional MXene-membranes, a novel membrane technology newly developed for CO2 sensing, capture and reduction. This technology is being developed for an over-arching goal of understanding changes in ocean carbon cycle and controlling CO2 level globally. The efficiency of such a device will be discussed from the view point of fluid dynamics.