Abstract
This study investigates the dispersion characteristics of pollutants around a group of tall buildings (hereafter a cluster), focusing on the effects of different source locations within and around the cluster. The wind tunnel experiments included simultaneous tracer concentration and three-component velocity measurements. Some of the experimental cases showed marked bi-modal plume shapes. A bi-Gaussian distribution fitting was used to delin-eate the plume boundaries. Results demonstrate that the location of the pollutant source notably affects plume development. Specifically, upstream sources (relative to the cluster) lead to a more uniform pollutant distribution , whereas central sources (within the cluster) result in bimodal concentration profiles. Analysis of pollutant fluxes in both horizontal and vertical planes reveals distinct scalar transport characteristics across different wake regions. In proximity to the cluster, a gradient transport model approach highlighted that upstream sources experienced greater advective transport, whereas sources within the cluster exhibited stronger turbulent mixing.
