Dynamic propagation of ice-water phase front in a supercooled water droplet

摘要

A three-dimensional (3-D) theoretical model is proposed to take the crystallization kinetics into the consideration of heat transfer, which allows for the description of the entire freezing process of a supercooled water droplet with the inclusion of the description of recalescence. The temporal evolution of the temperature and solid mass fraction at various stages during freezing are numerically studied, which shows a good agreement with the experimental results of the water droplet frozen in cold nitrogen gas stream. In particular, the ice-water phase front dynamics initiated from a single ice nucleation site is numerically investigated in recalescence stage, which shows that the ice-water phase front spreads over the entire water droplet with a diameter of 1.4 or 2.0 mm within about 16.0 or 23.0 ms governed by crystallization kinetics, leading to the drastic increase of the temperature and solid mass fraction of the droplet under the effect of thermodynamics. The present theoretical model can be useful to describe the dynamic behavior of ice crystallization in many other relevant cases.