线源扩散的模拟计算

在传统的高斯扩散理论基础上，提出了一种计算线源扩散的方法；将公路线源分成若干存在初期扩散的单元，每个单元近似成一个过单元无中心与风向垂直的短子线源，它的扩散按高斯垂直风模式计算，测点的浓度是若干子线源的贡献之和。与ＣＬＩＮＥ２等模式相比，该方法对任意风向有限长线源都适用，而且可进行一条公路上有不同源强路段的计算，模式的计算结果与现场示踪及尾气污染的实测数据吻合较好。

Mathematical Modelling on the Dispersion of Line Sources of Air Pollution

Based on the traditional Gaussian dispersion theory,a method has been proposed to calculate the dispersion of line sources of air pollution caused by vehicles runing on road. In this method,a road line source is divided into several elements in which an initial dispersion exists; each of the elements is considered to be a proximate short line source which is passing through the midpoint of the element and is rectangular to the direction of wind, and can be calculated for its dispersion based on the Gaussian Model for rectangular wing, with the concentration of pollutants at a measuring site being a sum of the contributions from all the short line sources divided.As compared with other models such as CLINE2,this method is applicable to all the line sources of finite length in an arbitrary wind direction and can be used to calculate for a reach with different intensities of sources on a road.The results of modelling calculations are consistent well with the data from field tracing and really measuring the pollution by vehicles exhausts.