A Numerical Model on Flow Field and Concentration Distribution in An Urban Street Canyon

At present,the main method on flow field and concentration distribution within an urban street canyon is observation and experiment.In this article,in order to predict the dispersion characteristics of vehicle emission pollutants in an urban street canyon,a three-dimension numerical model was developed based on artificial compressibility method and a K-E model.This three-dimension numerical model has been evaluated using the database from a set of street canyon experiments carried out in an urban street canyon of Lanzhou city in July 1995,it shows that the numerical model is accurate and useful for predicting the wind distribution and the air quality within an urban street canyon under the terms of different wind speed and wind direction,street canyon's height/width ratio and different building symmetry.