Numerical investigation to examine two methods of passive control in urban street canyon using CFD: Comparison between crossing under building and solid barriers lbw

Different passive control methods are discussed in this paper with the purpose of improved the quality of the air and dispersed the pollution outside the urban canyon road. Numerical investigation model is used in this paper, to examine two methods of passive control within a crossing under building and Low Boundary Wall in center of road for reducing air pollution concentration using Reynolds-averaged Navier–Stokes  equations and the k-Epsilon turbulence model as close of the equation system. The results of this investigation show that a low boundary wall located at the central median of the street canyon creates a significant reduction in pedestrian exposure, relative to the same canyon with no wall. The magnitude of the exposure reduction was also found to vary according to the numbers of the crossing under building in the street canyon geometry. The values of the concentration normalized is  decreased in the critical region were located in the centerline of the street canyon.Keywords: Passive Methods, Barriers, Street Canyon, Pollutant  Dispersion, Numerical Simulation