Wang Liwei, Dai Jinzhao, Hao Pengfei, He Feng, Zhang Xiwen
AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China.
ACS Omega. 2020 Feb 11;5(7):3322-3332. doi: 10.1021/acsomega.9b03415. eCollection 2020 Feb 25.
We present a numerical model to study the dynamic behaviors and heat conduction of freezing liquid droplets based on the MDPDE method (many-body dissipative particle dynamics with energy conservation configurations). In this model, the freezing processes involved in cooling, recalescence, and nucleation are considered. A new scaling method was developed to connect the mesoscopic MDPDE coefficients and macrothermal conductivity. The freezing of water droplets on cold surfaces with different wettabilities was simulated. Both the evolution of temperature and ice-liquid interface movement showed close agreement with the experimental data. We discuss the formation of a pointy tip on the top of an ice-drop and nucleation and growth during the recalescence stage. The rapid expansion of the recalescence region and the growth of the solid-phase region were calculated numerically, and this showed that the nuclei distribution of the two processes were completely different. The MDPDE model can not only predict the freezing time and shape deformation of ice-drops but also the nuclei formation and crystal growth during solidification. This study provides a useful tool for deicing material design.
我们提出了一个基于MDPDE方法（具有能量守恒构型的多体耗散粒子动力学）的数值模型，用于研究冷冻液滴的动态行为和热传导。在该模型中，考虑了冷却、再辉和成核过程中的冻结过程。开发了一种新的标度方法，以连接介观MDPDE系数和宏观热导率。模拟了不同润湿性的冷表面上水滴的冻结过程。温度演化和冰 - 液界面运动均与实验数据显示出密切的一致性。我们讨论了冰滴顶部尖点的形成以及再辉阶段的成核和生长。对再辉区域的快速扩展和固相区域的生长进行了数值计算，结果表明这两个过程的核分布完全不同。MDPDE模型不仅可以预测冰滴的冻结时间和形状变形，还可以预测凝固过程中的核形成和晶体生长。该研究为除冰材料设计提供了一个有用的工具。
