气体分子扩散的蒙特卡罗模拟

使用蒙特卡罗方法,对气体分子在背景气体中扩散的过程进行了计算机模拟,背景气体均匀分布于三维无界空间中。模拟结果显示,气体分子的扩散是各向同性的,扩散经历的时间越长,分子分布的范围越大,分子扩散的方均位移与时间成正比关系。使用本文的模拟方法还可估算气体扩散系数的数量级,对1标准大气压下、15°C时氧气的自扩散系数,以及氧气在氮气中的互扩散系数进行了估算,得到的扩散系数数量级与实验测量结果符合得很好。

MONTE CARLO SIMULATION OF DIFFUSION OF GAS MOLECULES

Based on Monte Carlo method, a computer simulation is performed to study diffusion process of gas molecules in background gas, which is uniformly distributed in three-dimensional unbounded space. The simulation results show that diffusion of molecules is isotropic which the longer diffusion time, the larger distribution range of molecules and the mean square displacement are proportional to time. The simulation method can be used to calculate the order of magnitude of diffusion coefficients of gases. The self-diffusion coefficient of oxygen and the mutual diffusion coefficient of oxygen and nitrogen are estimated at 1 atmosphere and 15℃ The calculated order of magnitude of diffusion coefficients is in good agreement with experimental results.