汽液平衡界面微观特征与应力特性的分子动力学研究  

A molecular dynamics investigation of microscopic characteristics and stress properties of the liquid-vapor equilibrium interface

作　　者：时雯[1,2] 何川[1,2] 李少华[1,2] 

机构地区：[1]重庆大学教育部低品位能源利用技术及系统重点实验室,重庆400044 [2]重庆大学动力工程学院,重庆400044

出　　处：《应用力学学报》2014年第1期32-36,3,共5页Chinese Journal of Applied Mechanics

基　　金：科技部重大专项基金(2009zx07104)

摘　　要：采用Verlet-List和动态存储的分子动力学方法,对饱和汽液平衡体系中的分子行为进行了模拟,研究了汽液界面的微观物理特征和应力特性以及温度变化对汽液界面热力学性质的影响。结果表明:汽液界面在空间和时间上都是涨落起伏的非稳定区域,且分子由液态向气态转变是一个突变过程;汽液过渡区厚度与局部界面涨落区宽度相同,验证了汽液过渡区和分界面涨落区的统一性;当温度从0.7变化至1.1时,气液界面厚度从4增加到9.5,而表面张力和两相密度差则不断减小;当温度接近临界温度时,系统表面张力趋近于0。The molecular behaviors of saturated liquid-vapor equilibrium system are simulated by molecular dynamics simulations of Verlet-List method and dynamic storage. The microscopic physical characteristics, stress properties and influence of temperature change on thermodynamic properties of liquid-vapor interface are studied.The results show that: the liquid-vapor interface fluctuates up and down in both space and time at a unsteady state and the transition of molecules from liquid to gas is a mutation process; the thickness of liquid-vapor transition zone is the same as the width of partial interfacial fluctuation zone and it is verified that the liquid-vapor transition zone and the interfacial fluctuation zone are consistent; when the temperature changes from 0.7 to 1.1, the thickness of liquid-vapor interface increases from 4 to 9.5 though surface tension and two-phase density difference are constantly reducing; when temperature close to critical temperature, the surface tension of the system tends to 0.

关 键 词：分子动力学 汽液界面 微观特征 表面张力 

分 类 号：TK123[动力工程及工程热物理—工程热物理]