Large-eddy simulations of scalar dispersion around an idealized building

Pollutant dispersion in urban environments is strongly influenced by the complex roughness geometry of the urban canopy. Detailed simulations of idealized geometries can provide vital insight into fundamental flow physics and can facilitate the development of reduced-order models. Here, Large Eddy Simulations (LES) are performed for the fluid flow and passive scalar transport from point releases near a simplified cubical building geometry using a spectral element method code. A thorough validation is conducted for the velocity field to ensure the sufficient accuracy of the LES approach compared with Direct Numerical Simulations (DNS) from the literature. The LES results provide a detailed characterization of scalar dispersion and its relation to flow structures and a Lagrangian description of the flow.