Three-dimensional Numerical Simulation Of The Flow Field And Pollution Concentration Field In Street Canyon Structure

Along with urbanization process aggravating, the buildings more and more concentrates. The street canyon structure has the enormous influence to the city air flow condition. The street canyon structure is the most active place where the inhabitant lives, therefore, the research on the flow field and the pollution concentration field of the street canyon structure has the vital significance, and becomes the domestic and foreign hot topic.At present, mainly research on the street canyon structure is the two-dimensional scale, but which does not obviously agree with the fact. From the three dimensional scale, we simulate the flow field and the pollution concentration field of eight different geometry size street canyon structures, and two simple blocks.The Spalart-Allmaras turbulent model is used to simulate the flow field, and the convection-diffusion model which couples with the flow field is used to simulate pollutant concentration field. The finite element method is used to discrete differential equation.The simulated result indicate that the street canyon structure geometry size has very tremendous influence to the flow field and pollution concentration field's distribution., The street canyon structure with smaller width and higher height has the more complex flow field, and the pollutant will be not easy to diffuse. We simulate and analyze the flow field and pollutant concentration field's distribution of the street canyon structure with different geometry size and in different position, which has the vital significance to the domain of urban planning and designing, the urban climate and the city air quality controlling, and so on.