Large Eddy Simulation of Pollutant Dispersion in a Building Complex

초록

Pollutant dispersion in turbulent flow around a building complex was numerically studied by LES. The original motivation of this work stemmed from the efforts to obtain an efficient technique for predicting dispersion of hazardous pollutants in a building complex. Such a technique would be invaluable in preventing or promptly responding to chemical accidents in dwellings or office buildings. First of all, the code was validated by comparing with other authors’ results on scalar dispersion in turbulent channel flow. Next, dispersion of car exhaust gas in a street canyon was simulated. A Lagrangian-averaged scale-invariant dynamic subgrid-scale model was used for both velocity and scalar fields, and a log-law-based wall model was employed on all the solid surfaces including the ground and the surface of buildings to replace the no-slip condition. The shape of buildings was implemented on the Cartesian grid system by an immersed boundary method.