This is particularly the case in congested, confined, or semi-confined areas in which local geometric details, such as topography or building geometry, may strongly influence the wind field and hence the contaminant dispersion.
We have used CFD in consequence assessment of several scenarios comprising intentional release of toxic materials in indoor environments, for example railway stations and convention centres.
Furthermore, we have also investigated outdoor contaminant dispersion from industrial facilities - examples include legionella bacteria from a biological treatment plant, dense toxic gas (chlorine) from an assumed tank rupture, and release and dispersion in idealized and real urban settings. The role of stratified weather conditions on contaminant dispersion, such as inversion, is currently under investigation.
Release from pressurized vessels is being studied using detailed two-phase simulations. The subsequent dispersion of heavy gas in an urban environment is also simulated, in particular with a view to assess turbulence models that adequately account for the stable stratification in the dense gas plume.
Several aspects of fundamental importance to the release and dispersion of toxic industrial chemicals will be investigated in the near future. Modelling of dispersion sources, in the form of initial concentration clouds, diffusive point sources, convective mass flux sources and detonations will be studied.