Freezing dynamics of wetting droplet under a uniform electric field

Electrofreezing is a powerful technique that employs the electric field to control and enhance the freezing process. In this work, a phase-field-based lattice Boltzmann (LB) method is developed to study the electrofreezing process of sessile droplet on a cooled substrate. The present LB method is first validated through performing some simulations of the three-phase Stefan problem, the droplet freezing on a cold wall, and the droplet deformation under a uniform electric field. Then we adopt this method to investigate the effect of electric field on the freezing of a wetting droplet on a cold substrate, and mainly focus on the droplet morphology, internal flow pattern, heat transfer, and also the freezing time. The numerical results show that the electric field has a significant influence on the freezing time of the droplet mainly through changing the morphology of the droplet. In particular, under the effect of the electric field, the freezing time is increased for the droplet with a prolate pattern, while the freezing time of the droplet with an oblate pattern is decreased. These numerical results bring some new insights into the role of electric fields on the electrofreezing process.