Abstract: Ships are prone to icing when navigating in polar low-temperature environments. Excessive ice accumulation can affect ship stability, operational safety, and operability of deck equipment, posing a serious threat to crew safety and hindering the rational development and utilization of polar regions. Ship icing is mainly caused by the splashing of waves, and its physical process can be regarded as the freezing process of a large number of saltwater droplets on a cold surface. Experimental research on the freezing process of a single saltwater droplet is essential for deeper understanding of the mechanism of ship superstructure icing at the mesoscale. For this, experiments are conducted on the freezing and melting of freshwater droplets on cold surfaces, the progress of the phase interface during the freezing process of freshwater droplets, the shape changes of water droplets after freezing, the freezing and melting time are recorded, and the influencing factors of the freezing process of freshwater droplets are analyzed. A saltwater droplet freezing experiment with a 3.5% mass fraction is also conducted, the shape changes, freezing and melting times after freezing are recorded, and the impact of droplet volume and cold surface temperature on the freezing process of the saltwater droplets are analyzed and discussed. The influence of salinity is analyzed and compared by comparing the freezing and melting experimental results of saltwater with those of freshwater droplets. The research outcome can provide data support for the validation of ship icing prediction models and scientific guidance for the development of anti-icing and deicing technologies on structural surfaces.

Key words: polar vessels, superstructure, freeze, saltwater droplets, freezing experiment

摘要： 船舶在极地低温环境中航行时容易发生结冰现象,积冰量过多会影响船舶稳性、运行安全性和甲板设备可操作性等,严重时会威胁船员安全,阻碍正常工作的开展。船舶结冰主要以海浪飞溅结冰为主,其物理过程可视为大量盐水滴在冷表面的冻结过程,对单个盐水滴冻结过程的实验研究是深入理解细观尺度船舶上层建筑结冰机理的必要过程。为此,该文开展了冷表面淡水滴冻结与融化实验,记录淡水滴冻结过程中固-液界面的推进过程、冻结完成后水滴的形状变化、冻结与融化所需时间,并完成淡水滴冻结过程影响因素分析;开展了质量分数为3.5%的盐水滴冻结实验,记录其冻结完成后的形状变化、冻结与融化所需时间,并分析讨论了水滴体积和冷表面温度对盐水滴冻结过程的影响规律;通过对比盐水滴与淡水滴冻结与融化实验结果,分析了盐度的影响。相关成果可为船舶结冰预报模型的验证提供数据支撑,并为结构表面防除冰技术的开发提供科学指导。

关键词: 极地船舶, 上层建筑, 结冰, 盐水滴, 冻结实验