Large-eddy simulation of pollutant dispersion in generic urban street canyons: Guidelines for domain size

Abstract Pollutant dispersion in urban street canyons has been widely investigated by large-eddy simulation (LES). Many LES studies focused on generic under a wind direction perpendicular to the axis. Accurate simulations require sufficiently large domain size minimize effects of artificial boundary conditions at faces results. As opposed RANS simulations, there is lack guidelines for an appropriate flow and pollutant canyons. The present study systematically investigates effect width, height upstream downstream lengths within 2.5D canyon with spanwise periodic conditions. Following validation study, 16 are performed different sizes. results show that minimum requirement width 2.5H, where H roof canyon. For height, length length, 7.5H, 5H 10H recommended, respectively. These should help reduce computational costs this type without significantly compromising accuracy.