The impact of building configuration and wall heating on pollutant dispersion in urban street canyon

This paper studies the impact of different building configuration and wall heating effect on flow field and pollutant dispersion in urban street canyon using the computational fluid dynamic (CFD) technique. Different street canyon configurations are considered according to the ratio of the building height and the street width H/W. It was found that (1) In symmetrical urban street canyon, heating up leeward building wall had little influence on the wind flow structure and pollutant dispersion. However, when the ground surface, windward building wall or all surfaces were heated respectively, the vortex structure in the canyon was significantly changed and directly influenced the pollutant dispersion in the canyon, (2) Due to upward buoyancy force from the wall heating changed the single vortex into multi-vortices, the pollutant no longer only accumulated on the one side but on both sides of the buildings together compared to isothermal condition in the street canyon.