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采用分子动力学模拟方法研究了强度为4.0-40.0 V·nm-1的均匀电场对过冷水冰晶结构和冰晶生长速率的影响.文中通过CHILL算法来识别不同的冰相结构,通过拟合Avrami公式来得到冰晶生长所需的特征时间.结果表明,在所施加的电场强度范围内生成的冰相以立方冰为主.随着电场强度的增加,形成的立方冰的变形程度逐渐增大,冰晶的密度从0.98 g·cm-3增加到1.08 g·cm-3,同时冰晶生长的特征时间从5.153 ns减小到0.254 ns,冰晶生长的速率逐渐增长.对水分子的动力学分析表明,冰晶生长速率增加的部分原因是电场能够促进水分子运动到形成冰晶所需要的取向.此外,对冰相分子形成过程的分析表明缺陷冰分子在冰晶的生长过程中扮演着中间态的角色.随电场强度的增加,由缺陷冰转变为立方冰的比例增长的速率逐渐提高.
The effect of uniform electric field with the intensity of 4.0-40.0 V · nm-1 on the ice crystal structure and the growth rate of ice crystals was investigated by using the molecular dynamics simulation method. In this paper, different ice structures were identified by CHILL algorithm. By fitting the Avrami formula The results show that the ice phase is dominated by cubic ice in the range of applied electric field intensity.With the increase of electric field strength, the degree of deformation of the formed cubic ice gradually increases, and the ice crystal The density of ice crystals increased from 0.98 g · cm-3 to 1.08 g · cm-3, and the characteristic time of ice crystal growth decreased from 5.153 ns to 0.254 ns, and the growth rate of ice crystals increased gradually. The kinetic analysis of water molecules showed that the ice crystals The increase of growth rate is partly due to the electric field can promote the movement of water molecules to form the desired orientation of ice crystals.In addition, the analysis of the ice phase molecular formation process shows that the defective ice molecules play an intermediate role in the growth of ice crystals.With the electric field As the intensity increases, the rate of increase of the proportion of defects ice to cubic ice gradually increases.