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中国科学院大学学报 ›› 2016, Vol. 33 ›› Issue (2): 228-233.DOI: 10.7523/j.issn.2095-6134.2016.02.013

• 中国工程热物理学会2014年多相流年会专栏 • 上一篇    下一篇

离子诱导水蒸气核化过程的分子动力学模拟

张超, 王跃社, 李晨沛   

  1. 西安交通大学动力工程多相流国家重点实验室, 西安 710049
  • 收稿日期:2015-03-13 修回日期:2015-07-07 发布日期:2016-03-15
  • 通讯作者: 王跃社
  • 基金资助:

    国家自然科学基金面上项目(51576160)资助

Molecular dynamics simulation of water vapor nucleation induced by ions

ZHANG Chao, WANG Yueshe, LI Chenpei   

  1. State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China
  • Received:2015-03-13 Revised:2015-07-07 Published:2016-03-15

摘要:

大气中的离子对水蒸气核化过程影响很大.本文采用分子动力学方法模拟水蒸气均相核化和离子诱导核化.利用模拟结果分析不同离子带电量对水蒸气核化过程的影响.结果显示,3种情况模拟过程均经历3个阶段:诱导阶段、稳定核化阶段和聚并阶段.离子存在时,水蒸气成核过程诱导阶段缩短,核化速率增大,临界团簇尺寸减小,核化更容易发生.正二价离子比正一价离子对核化过程的影响更大.最后,利用团簇微观结构解释了模拟结果.

关键词: 团簇, 离子, 核化, 分子动力学

Abstract:

Ion has an important effect on the water vapor nucleation. In this study, molecular dynamics method was employed to investigate the homogenous and ion-induced nucleation processes of supersaturated steam. Effects of charge magnitude on the nucleation process were analyzed based on the results of the molecular dynamics simulation. It has been observed that the process in each case consists of three stages: induction stage, stable nucleation stage, and coagulation stage. The presence of ions leads to shorter induction stage, increase of nucleation rate, and decrease of critical nucleus size, which means that the nucleation process is easier to occur. Moreover, positive divalent ions have greater influence on water vapor nucleation than positive monovalent ions. Finally, the phenomenon is explained using the cluster's micro structure.

Key words: cluster, ions, nucleation, molecular dynamics

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