Study on a mesoscopic model of droplets freezing considering the recalescence process

There are many practical applications of droplets freezing, and in many cases, it is necessary to prevent the droplets freezing to reduce the loss caused by freezing. Based on the many-body dissipative particle dynamics with energy conservation method, this research proposes an icing model that considers the recalescence process and initial ice mass fraction of droplets for the first time, which obtains a complete simulation of the two-phase four-stage freezing process of droplets. The accuracy and applicability of this model are verified by studying the single-phase Stefan problem, the recalescence process of droplet, and whether the initial ice mass fraction is considered for freezing. Then, the freezing process of droplets under four surface temperatures and five types of surface wettability was studied, and it was found that the temperature of droplets in recalescence stage would jump from nucleation temperature to equilibrium temperature, and almost unaffected by external factors. Change of the temperature distribution with dimensionless height H * before recalescence is only affected by the surface temperature and nucleation temperature. At the end of droplets recalescence, the initial ice mass fraction has little relationship with volume. As the contact angle, surface temperature, and droplet volume increase, temperature changes in the pre-cooling and solidification stages of droplets will slow down, and the solidification time will increase. Additionally, the temperature of the solid wall surface has almost no effect on the final ice shape, and the final ice tip phenomenon is more obvious on the surface with a larger contact angle.