The effect of baffle plate on pollutant dispersion inside an isolated street canyon by CFD modeling

Deep street canyons and unfavourable meteorological conditions usually induce high pollutant exposure.Two-dimensional numerical simulations were performed to investigate the impacts of vertical baffle plate on flow and pollutant dispersion inside an isolated street canyon. The simulate results were validated by wind tunnel experiment. The contrast model was established without baffle plate that defined as case 1. Other models with baffle plate with(0.005m,0.0075m,0.01m,0.0125m,0.015m,0.02m,0.03m) away from the canyon roof were defined as case 2 to case 8 respectively. All geometric models are 1:500 reduced scale in this paper. The numerical results reveal that baffle plate has significantly effect on flow patter and pollutant distribution in street canyon. For dimensionless average pollutant concentration, case 3 experience the greatest pollutant exposure reduction which followed by case 2. From case 4 to case 8, with increasing, pollutant dilution effect become increasingly weak. The study results are helpful for the prevention and control of pollutants in street canyon.