Observational experiment and numerical simulation of air pollutant dispersion in Yuzhong

Based on the data from the field experiments in Yuzhong city of Gansu Province in China, flow field and tracer gas dispersion were simulated by using a CFD model Fluent. Firstly, a 3-dimensional urban building model was created by using the Gambit software according to the measured data, and then inputted into the Fluent model for computation. Comparison of the simulated wind and pollutant dispersion with the observed data showed that the simulated results were reasonable. The total similarity coefficient of wind direction and speed between simulated and observed data were 0.876 and 0.843, respectively, and the correlation coefficient of pollutant between simulated and observed data on the plane 0.5 m and 27 m above the ground level were 0.71 and 0.72, respectively. Therefore, the fluent model can be used for studying urban pollutant dispersion, and guiding the setup of air quality monitoring station based the simulated results.