| It is widely used a road tunnel in city as extended and complement of road system on ground, and it is more important that research about road tunnel ventilation .But the most research is focusing on traffic secure in tunnel ,it is a little the research about contaminator diffusion in air. According the existing condition, it is used for systematically research by CFD method, which numerical simulate contaminator distribution in air of a city road tunnel portal.In this paper, KangWang tunnel in Guangzhou city is research target .According this tunnel actual size to build 3D physical mathematic model, STAR—CD software is used to realize three-dimensional simulation. N-S equation is governing equation of computation and k -εturbulent model is employed. The finite volume method is used to discrete the computed area. When dealing with the boundary condition in the area near the wall. SIMPLE method is used for solving.In this paper, it is simulation that contaminator diffusion law in different exit velocity from the road tunnel. Comparing analyze of different exit velocity effect concentration field, and suggest the best exit velocity. As typical work condition which are normal ventilating work condition and jam traffic ventilating work condition, different season wind and several typical direction of wind effect diffusion. It is compared with contamination distribution about sensitive lengthwise section which are pavement and building which people long exposure. Through these research, the wind effect contamination distribution, and know the area which is easily super-standard and the distributing regular of the area. The research results show that the contaminator which is satisfy with ventilation standard in tunnel is over standard in the area around road tunnel portal. It is needed that adopt some way to lower the concentration in the area. So it is suggest that build air shaft or open a hole in tunnel. |
PDF Full Text Request