Numerical assessment of pollutant concentration distributions around buildings

The accuracy of Computational Fluid Dynamics (CFD) in the prediction of the pollutant concentration distributions around buildings has been assessed by validating the results of CFD simulations with wind tunnel experiments. Three different cases, each with an increasing complexity, have been investigated: a model of an isolated stack, a model combining a single building and stack, and a model of an actual urban area in downtown Montreal, Canada. For each case, the turbulence model, turbulent Schmidt number and boundary conditions were varied. In most instances CFD was able to predict the pollutant concentration within a factor of 2-3 from the wind tunnel experiments, but no consistency was found in the best performing turbulence model, turbulent Schmidt number and boundary conditions