微孔中简单流体混合物扩散系数的分子动力学模拟与关联  

Diffusivity of Simple Fluid Mixtures in Porous Media: Molecular Dynamic Simulations and Correlation Models

作　　者：秦星[1] 张秉坚[1] 张晖[1] 胡文暄[2] 

机构地区：[1]浙江大学化学系,杭州310027 [2]南京大学地球科学系,南京210093

出　　处：《Chinese Journal of Chemical Physics》2003年第6期467-471,共5页化学物理学报（英文）

基　　金：ProjectsupportedbytheNationalMajorFundamentalResearchandDevelopmentProject (G19990 4 33)andtheNationalNaturalScienceFoundationofChina (2 99770 18)

摘　　要：为了了解简单流体混合物在微孔介质中的流动和传递性质 ,对微孔中氩和氪流体混合物的扩散系数进行了计算机模拟和关联模型研究 .运用平衡分子动力学方法模拟了宏量条件下饱和氩流体的扩散系数和恒温氪流体的扩散系数 ,模拟值与文献实验值符合良好 ,从而程序的正确性得到验证 .然后 ,采用类似Bitsanis等人的方法模拟了平板湿壁微孔中氩和氪等摩尔流体混合物在不同对比温度、不同对比密度以及不同对比孔径条件下的扩散系数 ,发现孔径很小的时候扩散系数会急剧的增大 .同时基于这些模拟值 ,参考CE理论和Heyes关系式 ,以对比温度、对比密度以及对比孔径为变量 ,关联出两个简单流体等摩尔混合物在微孔中扩散系数的计算模型 .It is well know that molecular dynamics simulations can provide an insight into the microscopic characters and relate them to the microscopic properties, and MD simulations are widely used to study the microscopic flows in porous media. The diffusivity of Lennard-Jones liquid argon, krypton and their binary mixtures in the macrovolumen systems has been calculated by equilibrium molecular dynamic (EMD) simulations in order to prove this program's validity. In addition, the diffusivity of liquid mixtures of argon and krypton in slit porous media has been obtained by EMD simulations at different reduced temperatures, densities and pore widths. The result shows that the diffusivity of fluids will increase sharply in narrow pores. Based on the Chapman-Enskog theory and Heyes equations, two correlation models, which can describe the diffusivity of simple fluid mixtures in porous media, are proposed as functions of the reduced temperature, density and pore width.. The results calculated from the models are in good agreement with the data from MD simulations.

关 键 词：分子动力学 扩散系数 简单流体混合物 微孔 模拟 关联分析 

分 类 号：O641.1[理学—物理化学]