Modeling the dispersion of pollutants in the surface layer of the atmosphere, taking into account the influence of buildings and terrain

Abstract

Traditionally, the assessment of atmospheric air pollution is done on the basis of data on pipe heights, temperature, velocity, volume and specific properties of the ejected aerosol, corrected for the prevailing wind direction and other changes. The tolerances of this technique are very large: as a rule, these are average weather conditions and a single source. The dispersion of pollutants depends on the conditions of their emission, transfer and turbulent mixing. The paper considers the characteristics that affect the stability of the surface layers of the atmosphere and determine the processes of turbulent transport.

In this paper, we propose a method for calculating the dispersion of pollutants in the surface layer of the atmosphere, based on the methods of computational fluid dynamics. The use of this technique makes it possible to take into account the influence of complex terrain and the nature of development. As an example of calculating the spread of pollutants, the paper considers the calculation of acetone emissions from a separate source located in the immediate vicinity of the building. The presented results of calculations clearly show the complex nature of the distribution of concentration fields in the immediate vicinity of buildings, as well as in conditions of dense buildings and complex terrain. Modeling such a complex distribution is practically impossible without the use of a powerful apparatus of computational fluid dynamics.