The study on the impinging freezing of the supercooled droplet containing the atmosphere aerosol

The aerosols have significant effect on the nucleation of supercooled droplet in the atmosphere. In this paper, the impinging freezing and static isothermal freezing experiments of the supercooled droplet were conducted to investigate the effect of potassium feldspar (K-feldspar), as the representative of aerosols, on the impinging freezing process. The results show that the impingement has more effect than K-feldspar on the freezing of supercooled droplet on the cold substrate. However, the K-feldspar can increase the impinging freezing probability of supercooled droplet further, and the higher the concentration of K-feldspar, the greater the influence. The freezing probability model in the static freezing and impinging freezing was established. Significantly, these freezing probability curves of K-feldspar suspension are exponential function and linearly proportional to the concentration approximately. However,the K-feldspar has little effect on the nucleation time during the impinging freezing. Moreover, by comparing the impinging freezing process, not only the nucleation but also the ice growth could be affected by the K-feldspar, leading to different final freezing morphology. The horizontal growth rate of ice could be increased by 3-10% because of K-feldspar, and the higher the temperature, the more the increase. Finally, according to the nucleation and ice growth process, the spreading ratio model was established and could predict the spreading ratio on various substrates. Spreading ratio of K-feldspar suspension is higher than pure droplet.