摘要
本文采用分子动力学方法对水蒸气在纳米硅固体颗粒上的异质核化过程进行了研究。氩原子作为载气,与水蒸气进行热量交换,带走水蒸气核化释放的热量;模拟系综初始温度为450 K,载气温度恒定为200 K。结果表明,核化初期小团簇由几个水分子组成,然后小团簇聚并形成大团簇,核化在纳米固体颗粒上的团簇为最大团簇。通过对比发现,异质核化系综内纳米固体颗粒能够促使核化发生,异质核化温度为360 K,高于353 K的均质核化温度。根据团簇分析,在同等条件下水蒸气异质核化率与均质核化率数量级相同,比理论预测值低一个数量级。
Molecular dynamics simulation was employed to explore the mechanism of heterogeneous nucleation of water vapor on silicon solid particle. Argon vapor was used as the carrier gas to remove the heat generated during the nucleation process. The initial temperature of system is 450 K and carrier gas temperature is rescaled at 200 K after the equilibrium state reached. Small clusters are formed by a few of water molecules in the beginning of nucleation process, then the formed clusters coalesce together to larger ones. Among these clusters, the largest cluster is the one related to the solid particle in the center. The results show that the solid particle plays significant roles in heterogeneous nucleation progress. The temperature of heterogeneous nucleation was 360 K and higher than the temperature 353 K of homogeneous nucleation. The nucleation rate of heterogeneous nucle- ation obtained from the cluster analysis was the same order of magnitude compared with the one in homogeneous nucleation and one order of magnitude lower than the prediction value by theory analysis.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2013年第10期1813-1817,共5页
Journal of Engineering Thermophysics
基金
高等学校博士学科点基金资助(No.20090191110016)
关键词
异质核化
团簇
核化率
分子动力学
heterogeneous nucleation
cluster
nucleation rate
molecular dynamics
