CFD Modeling of Aerial Dispersion of Pollutants in Urban Environments

Population growth and urbanization across the globe is contributing to anincrease in air pollution emissions. Because air pollution can negatively impact public health there is a desire to model the aerial dispersion of the pollutants in urban environments. Computational Fluid Dynamics (CFD) is becoming an increasingly common tool used to provide high spatial and temporal resolution of the wind flow and pollutant transport in urban environments. In the present study, CFD is utilized to model the aerial pollutant dispersion in three domains: a flat field, an idealized urban environment, and a real urban environment neighboring the Jones’ Island Water Reclamation Facility with topography. A new method which utilizes meteorological data with high temporal resolution (one minute) is proposed to improve the lateral dispersion of pollutants in standard CFD studies where hourly-averaged data is used. The proposed and standard methods are tested in the three domains. The idealized cases (flat field and idealized urban environment) are validated using AERMOD, an empirically formulated Gaussian Plume Model, while the real domain is validated using field measurements. The proposed method improves the lateral dispersion in the flat field, but deviates from AERMOD in the idealized urban domain. In the real urban domain, the proposed method shows promise and is able to capture of the qualitative trends in the domain. However, CFD with hourly averaged meteorological data, instead of one minute, appears to provide a slightly better match with the field measurements