中文摘要：

采用激光衍射瞬时浓度场测量系统和图像处理系统，对不同高架与周围建筑高度比下污染点源绕建筑对流扩散进行了风洞实验．Fluent双相耦合模型与实验进行了相互校核，得到了建筑的各个高度层面污染分布、不同高度比下的污染扩散及污染分布随时间变化的规律。不同高度比对污染对流扩散具有明显的影响，建筑各高度层面污染浓度分布也存在明显差别。当高度比较小时，污染将堆积在建筑物底层。污染分布随时间变化有助于了解污染对流扩散的时间效应。结果可以为高架与周围建筑规划提供参考与依据。

英文摘要：

Wind tunnel experiment was carried out to investigate the diffusion and dispersion of point source air pollution distribution in different heights of surrounding over-head roads and buildings. Laser Diffraction Instantaneous Pollutant Concentration Field Measurement System and Image Processing System were employed. Numerical simulation using Fluent and two-phase couple model was carried out, （1） Pollutant distribution in different heights of the building; （2） Pollutant dispersion in different height of the building; （3） Temporal variation of the pollutant distribution, were obtained and compared with the experiment. The result showed that： Height has significant effect on the diffu- sion and dispersion of the pollutant; obvious difference can be observed in the pollutant concentration distribution in different heights. Pollutant will tend to accumulate in the bottom of the building when the height ratio is small. Temporal variation of the pollutant concentration distribution can help understanding the time effect of the pollutant diffusion and dispersion, and the result of this paper can serve as a reference in planning of the construction of the over-head road and surrounding buildings.