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街道峡谷是城市地区典型的建筑结构,研究在不同气象条件下汽车尾气等污染物在街道峡谷内流动扩散的规律是近年来研究的热点.本文利用CFD技术对街道峡谷内流动扩散的风洞试验应遵循的相似准则进行了研究,结果表明对所研究结构的建筑模型雷诺数(ReH)大于临界值3×104之后,街道峡谷内流动结构不再发生改变,满足Re数无关性.在此基础上,满足模型与原型的密度弗劳德数(Frρ)相等,可以在最大程度上满足流动与扩散的相似条件.以Re数无关和Frρ数相等两个相似条件构建的风洞试验的结果,作为原型数值计算的验证条件,两种研究方法的结果有很好的一致性.“,”Street canyons are typical urban building structures.Recently,many studies have concerned on the flow and pollution dispersion characteristics around these urban structures.The similarity criteria of flow and dispersion in wind-tunnel experiments were investigated by CFD technology.The results show that the velocity distribution would be independent of Reynolds number for the structure studied if the building Reynolds number (ReH) is over the critical value ReH,crit =3×104.Furthermore,if the density Froude number (Frρ) of the model is equal to that of the prototype,the similarity criteria of flow and dispersion would be mostly satisfied.Based on the Re independence and Frρ equality,a good agreement was achieved between numerical simulation and wind-tunnel experiments.