Modeling of turbulent atmospheric boundary layer and dispersion of solid pollutant particles in an urban area using large eddy simulation

In this paper, the air flow field around buildings is simulated to predict the dispersion of the fine solid pollutants. The large eddy simulation approach has been used to model the turbulence flow. In the first part of this research, a simple model including a building has been simulated and the obtained results are compared and validated with the experimental data obtained from a wind tunnel test. By setting the optimal parameters of the numerical model in the first part, in the second part, an area of Tehran city with high-rise buildings and irregular urban layout is considered and the velocity field and deposition of the contaminant particles in this model are also simulated. The result obtained in the first part of show good agreement with the experimental data and in both models the effect of some variables like the arrangement of buildings (in urban model) and the wind velocity are investigated. To analyze the value of the pollutant concentration in the urban area at each time, the integral of this variable on some important surfaces has been calculated over time and the effect of urban area layout on the integration is discussed.