3634 両端にトンネルを持つ橋梁からの排気ガス拡散(S49-2 トンネルの空気力学と換気(2),S49 トンネルの空気力学と換気)  [in Japanese] 3634 Exhaust Gas Diffusion from the Bridge with Tunnels at both Ends  [in Japanese]

In urban tunnels, it is important to give enough consideration of protecting environment in the surrounding area, as well as maintaining environment in tunnel. In the paper, the authors analyze the dispersion phenomena of the exhaust gas from a bridge with tunnels at both ends. In this situation, the exhaustion gas, both from the tunnels and the bridge, is dispersed from the bridge originated. When considering higher protection of the environment of the adjacent area, possible measure would be the installation of louver. The analysis gives quantitative evaluation of the comparison between cases with and without louver by means of numerical simulation. The numerical analysis utilizes sliding mesh technique to express the movement of the vehicles, which enables realistic flow analysis. The convection-diffusion of the pollutants is analyzed. The results show that the louver gives little performance of suppressing pollution dispersion.