pollutant distribution meaning in English

污染物分布

First , the difference between the stm and utm is compared and analyzed . the results show that it can accurately simulate the unsteady flow process of piston wind and the pollutant distribution in tunnel after train left the tunnel , can analyze and calculate the good effect of inertial action of piston wind if using utm
文中首先分析和比较了传统隧道通风设计所采用的恒定流理论与非恒定流理论的差别，表明运用非恒定流理论不仅更能准确模拟隧道内活塞风的非恒定流动过程，而且能模拟列车通过隧道过程中隧道内污染物浓度的分布，同时还能考虑利用隧道内气流(活塞风)惯性作用促进隧道通风，节约通风能耗。