简单气体自扩散碰撞截面与温度关系的模拟  

Simulations on the temperature dependence of self-diffusion cross section of simple gases

作　　者：吕勇军[1] 李军刚[1] 刘鹏 LYU Yong-jun;LI Jun-gang;LIU Peng(School of Physics,Beijing Institute of Technology,Beijing 10081,China)

机构地区：[1]北京理工大学物理学院,北京100081

出　　处：《大学物理》2025年第1期49-52,56,共5页College Physics

基　　金：国家自然科学基金(52071029,52031016)资助。

摘　　要：气体的输运性质与分子间的碰撞过程有密切的关联,特别是碰撞截面对气体的自扩散、黏度和热导率有着重要的影响.本文采用分子动力学模拟方法系统研究了常压下单原子气体He、Ar,双原子气体N_(2)和多原子气体CH_(4)的自扩散系数及其温度依赖行为.基于简单气体的经典散射模型并结合模拟结果探讨了气体分子自扩散碰撞截面与温度之间的关系.本文结果对气体输运性质的教学与研究具有一定的指导意义.The transport properties of gases are closely related to the collision process between molecules,and in particular,the cross sections significantly affect diffusion coefficient,viscosity and thermal conductivity.This work studies the diffusion coefficients of He,Ar,N_(2) and CH _(4) as well as their temperature dependence using molecular dynamics simulations.Based on the classical scattering model of simple gases combing with the simulation results,the temperature dependence of self-diffusion cross section and its effect on diffusion coefficient are analyzed,which is helpful for the teaching and research of transport properties of gases in the course of college physics.

关 键 词：自扩散系数 碰撞截面 分子动力学模拟 

分 类 号：O552.3[理学—热学与物质分子运动论]