计算机模拟估算气体的扩散系数  

Estimating diffusion coefficients of gases by use of computer simulation

作　　者：晋宏营[1] 

机构地区：[1]榆林学院能源工程学院

出　　处：《计算机与应用化学》2012年第11期1294-1298,共5页Computers and Applied Chemistry

基　　金：陕西省教育厅科学研究项目(2010JK933)

摘　　要：使用计算机模拟了气体分子在背景气体中的一维扩散过程,结果显示:越靠近初始位置处,分子数密度越大;扩散时间越长,分子分布的空间范围越大;模拟的分子数越多,涨落越小;分子的方均位移与扩散时间成正比。本文的模拟方法可用来估算气体的扩散系数,对1标准大气压和15°C条件下,氩气、氢气、氮气、氧气、二氧化碳和氖气的自扩散系数,以及此条件下氢气在氧气中、氢气在氮气中、氢气在二氧化碳中和氧气在氮气中的互扩散系数进行了估算,并把估算的扩散系数和相应的扩散系数实验值作了对比,二者不但数量级符合的很好,数值也比较接近,说明估算较为成功。One-dimensional diffusion process of gas molecules in background gas is simulated by use of computer. The results show that the closer the distance between molecules and the initial position is, the larger the number density of molecules is; the longer diffusion time, the larger distribution range of molecules is; and the more the number of molecules, the less fluctuation is. The mean square displacement is proportional to the diffusion time. The simulation method can be used to estimate diffusion coefficients of gases. The self-diffusion coefficients of argon, hydrogen, nitrogen, oxygen, carbon dioxide and neon are estimated at 1 atmosphere and 15℃, and the mutual diffusion coefficients of hydrogen in oxygen, hydrogen in nitrogen, hydrogen in carbon dioxide and oxygen in nitrogen are estimated under the same condition. The estimative diffusion coefficients have been compared with the corresponding experimental values, and that shows not only orders of magnitude of them are in good agreement with each other, but also values are also relatively close to each other. This demonstrates that the estimation method is successful.

关 键 词：扩散系数 蒙特卡罗模拟 方均位移 平均自由程 

分 类 号：O552.2[理学—热学与物质分子运动论]