航空学报 > 2026, Vol. 47 Issue (4): 232342-232342   doi: 10.7527/S1000-6893.2025.32342

固体力学与飞行器总体设计

应力和温度对过冷水结冰影响的分子动力学模拟

汉芮岐1, 徐绯1,2(), 陈成1, 任战鹏3, 张惠3   

  1. 1.西北工业大学 航空学院,西安 710072
    2.强度与结构完整性全国重点实验室,西安 710072 3. 中国飞机强度研究所,西安 710065
  • 收稿日期:2025-05-30 修回日期:2025-07-30 接受日期:2025-08-18 出版日期:2025-09-08 发布日期:2025-08-28
  • 通讯作者: 徐绯 E-mail:xufei@nwpu.edu.cn
  • 基金资助:
    国家自然科学基金(D5110220438)

Molecular dynamics simulation of stress and temperature effects on supercooled water freezing

Ruiqi HAN1, Fei XU1,2(), Cheng CHEN1, Zhanpeng REN3, Hui ZHANG3   

  1. 1.School of Aeronautics,Northwestern Polytechnical University,Xi’an 710072,China
    2.National Key Laboratory of Strength and Structural Integrity,Xi’an 710072,China
    3.Aircraft Strength Research Institute of China,Xi’an 710065,China
  • Received:2025-05-30 Revised:2025-07-30 Accepted:2025-08-18 Online:2025-09-08 Published:2025-08-28
  • Contact: Fei XU E-mail:xufei@nwpu.edu.cn
  • Supported by:
    National Natural Science Foundation of China(D5110220438)

摘要:

过冷大液滴碰撞结冰的物理过程复杂,涉及液滴冲击动力学与凝固过程的耦合,其中温度、应力对冰形核、生长的影响引起了广泛的关注。采用分子动力学模拟方法,针对不同温度下过冷水结冰问题,建立了均匀形核、非均匀形核模型,研究了自然结冰、冰核结冰过程。分析了结冰比例达到70%后的径向分布函数特征,初步确定当研究对象的径向分布函数与立方冰一致,且在2.7×10-10、4.4×10-10 m 2个峰值处偏差分别小于10%、20%时可判断为结冰现象;计算了不同温度下非均匀形核模型的冰核临界数,在低于250 K温度下与经典形核理论给出的立方冰核临界数吻合;引入了载荷应力研究其对结冰过程的影响。结果表明,在剪切载荷、三向挤压载荷作用下,促进冰的形核、冰核生长的应变率不同,剪应变率为107~108 s-1,三向压缩应变率为105~106 s-1。冰的形核过程主要是由于成核势垒增大引起的阻碍效应与自扩散率增大引起的促进效应之间的竞争,冰核生长过程主要归因于自扩散率增大引起的促进效应。

关键词: 过冷水, 冰, 温度, 应力, 分子动力学模拟

Abstract:

The physical process of supercooled large droplet impingement freezing is complex, involving the coupling of droplet impact dynamics and solidification process, among which the influence of temperature and stress on ice nucleus formation and growth has received widespread attention. The molecular dynamics simulation method is employed to establish homogeneous nucleation and heterogeneous nucleation models for the freezing problem of supercooled water at different temperatures, and the natural freezing and ice nucleation freezing processes are studied. First, the radial distribution function characteristics are analyzed after the freezing fraction reached 70%. It is preliminarily determined that when the radial distribution function of the research object is consistent with cubic ice and the deviations at the two peaks at 2.7×10-10 m and 4.4×10-10 m are less than 10% and 20% respectively, it can be used as a basis for judging the freezing phenomenon. Then, the critical number of ice nuclei for heterogeneous nucleation models at different temperatures is calculated, which is consistent with the critical number of cubic ice nuclei given by the classical nucleation theory at temperatures below 250 K. On this basis, load stress is introduced to study its influence on the icing process. The results of this paper show that under the action of different load, the strain rates promoting nucleation and growth of ice are different. The shear strain rate is 107 - 108 s-1, and the triaxial compression strain rate is 105 - 106 s-1. The nucleation process of ice is mainly due to the competition between the hindering effect caused by the increase of nucleation barrier and the promoting effect caused by the increase of self-diffusion rate, and the growth process of ice nuclei is mainly attributed to the promoting effect caused by the increase of self-diffusion rate.

Key words: supercooled water, ice, temperature, stress, molecular dynamics simulation

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