Freezing dynamics of wetting droplet under a uniform electric field

TL;DR

This paper develops a phase-field-based lattice Boltzmann method to study how a uniform electric field influences the freezing process of a wetting droplet on a cold substrate, revealing electric field effects on freezing time and droplet morphology.

Contribution

The study introduces a novel LB method for electrofreezing, providing new insights into electric field effects on droplet freezing dynamics and morphology control.

Findings

Electric field significantly affects freezing time.

Electric field alters droplet morphology during freezing.

Freezing time varies with droplet shape under electric influence.

Abstract

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 accuracy of 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 it is used to investigate the effect of an electric field on the freezing of a wetting droplet on a cold substrate, and 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 on the electrofreezing and provide a valuable guidance for the precise regulation of droplet freezing.