| In this paper, a droplet freezing visualization experimental device was built, and three kinds of base plate materials, T2 purple copper (Ⅰ), 7075 aluminum alloy (Ⅱ), and 304 stainless steel (Ⅲ) were selected as the research objects. The effects of droplet volume and substrate temperature on droplet deformation were investigated, and the variation rules of relevant parameters in the phase transition process, such as freezing time, droplet height, and contact angle, were studied. It is found that under the combined influence of surface tension, density difference and gravity, the droplet deformation has a similar pattern: the height increases, the droplet profile changes from curved to conical, and the singular tip is formed, etc. The droplet deformation rate on the cold surface Ⅰ is the largest, and the difference in the growth rate of droplet height before and after freezing under the influence of volume is less than 10%. Among them, the droplet deformation rate on the cold surface Ⅰ is the largest, and the difference of the height growth rate before and after the droplet freezing under the influence of volume is within 10%. When the cold surface temperature was decreased from 268 K to 255 K, the cold surface Ⅱ was most affected by the cold surface temperature, and the drop rate was 15%. Compared with cold surfaces I and II, cold surface III has some delaying effect on droplet freezing and there is a transparent-like strip. The study of the deformation law of droplet freezing can better understand the freezing mechanism and provide certain data support for the anti-/de-icing technology in low-temperature environments in engineering examples. |
