Pollutant dispersion has become one of increasing concern to cities, laboratories, industrial areas and car parks where the concentration of the pollutant reduces the quality of a microclimate. GWTS pollution dispersion study uses desktop, wind tunnel and Computational Fluid Dynamics Study. The choice for particular method depends on the type of the project.
The location of exhaust stacks needs to be considered to minimize the entrainment of exhaust gas plumes. Above certain concentrations, these exhaust gases may be odorous and/or dangerous to health. For larger developments where numerous residential, commercial or industrial exhausts are collected, re-entrainment via building air intakes or open windows should be minimized. A “plume strike” on an apartment balcony should also be considered, as the results of such an event could be undesirable for the occupants who may be subjected to unpleasant odors.
Desktop study of pollutions dispersion study is based on experience, literature review and a simple Gaussian model. The desktop study is the initial assessment of the pollution dispersion for simple geometry and topography. This study also establishes the need for further study using wind tunnel or CFD.
Wind Tunnel Study
Wind tunnel test of pollutant dispersion is carried out at appropriate length scale with accurate modelling of plume discharge momentum and atmospheric velocity to measure complex aerodynamic effects. The relative concentration level in all selected locations will be determined for neutral atmospheric condition. If the effect of thermal gradient needs to be considered CFD will be used.
Computational Fluid Dynamics (CFD) Study
CFD is appropriate tool to model internal flow as well as the effect of temperature. CFD will be used to determine the pollutant concentration and the effect of temperature.