A mathematical model of wind flow, vehicle wake, and pollutant concentration in urban road microenvironments. Part II: Model Results

Theoretical formulations of the proposed model for prediction of pollutant dispersion in microenvironments were previously introduced in part I of this paper. This paper discusses the new model findings and presents model evaluation results. This paper first explains the current problems that the road environment causes in employing field data for wind and temperature collected along a road north of Nagoya, Japan. A complete simulation is done on wind components in street-canyon and wind distribution, including vehicle wake effect, and is evaluated with experimental results. Next, the paper provides the atmospheric stability and dispersion parameters and then predicts pollutant buildups estimated using several techniques: a numerical model, modified Gaussian dispersion model, and a stochastic model. The stochastic model is specially developed to predict pollutant buildups in microenvironments. Model sensitivity analysis is done, varying the physical parameters: vehicle dimensions to wind speed in microenvironments, vehicle dimensions to dispersion parameter, and wind speed to pollutant concentrations. The modeled results are then compared to experimental data collected in microenvironmental locations in a road of Nagoya City, Japan. Finally, the implications of the research findings are discussed.