F., . Baghlad1*B., . Douaiba1,A, Azzi1,2023-05-092023-05-092018-05-01F. Baghlad1*, B. Douaiba1, A. Azzi1, A. Alaswad2* .NUMERICAL INVESTIGATION TO EXAMINE TWO METHODS OF PASSIVE CONTROL IN URBAN STREET CANYON USING CFD: COMPARISON BETWEECROSSING UNDER BUILDING AND SOLID BARRIERS LBWN. Journal of Fundamental and sciences. vol.10, no 2. May 2018. Faculty of exact sciences. university of el oued. [visited in 01/05/2018]. available from [Saadatg561@gmail.com]http://dspace.univ-eloued.dz/handle/123456789/22454ARTICALDifferent 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.enPassive Methods, Barriers, Street Canyon, Pollutant Dispersion, Numerical Simulation.Article