Wind driven natural ventilation and pollutant dispersion in the dense street canyons: Wind Opening Percentage and its effects

In the present work, multi-scale flow phenomena across street canyons and built air motions are fully numerically simulated, regarding of effects of window opening percentages on the wind flow, energy and species transports. The results indicate that the exchange of air current between the upside and bottom of street canyons gradually enhances with the enlargement of window opening percentage, which also gradually dilutes the pollutant concentration in our target street canyon, bypassing those pollutants into the adjacent regions. Ventilation pattern inside the upper room is apparently different from that in the ground floor. In addition, window opening percentage tends to have more impacts on the pollutants distribution around leeward buildings. Present work can contribute to ameliorating air quality in street canyons by utilizing natural ventilation.