Determination of plume capture by the building wake

Abstract

Flow and dispersion about a cubical building were computed using a fourth-order accurate finite elements scheme. The time-averaged Navier-Stokes equations were closed with the standard k−ϵ turbulence model as well as with a k−ϵ turbulence model modified to allow production of turbulent kinetic energy to depend on the product of the strain rate and vorticity. The computed flow agreed with the wind tunnel measurements. Releases from a stack located at various positions within the recirculation zone behind the building were simulated. The effect of stack velocity on the concentration in the recirculation cavity was quantified by comparing the mass of pollutant in the recirculation cavity at very low stack exit velocities with the mass of pollutant in the recirculation cavity for higher stack exit velocities. The mass of pollutant in the recirculation zone decreased considerably at the higher stack velocities. The results of this work can be used to help develop and improve the modeling of pollutant transport in recirculation zones and wakes.