3626 多孔板によるトンネル内を伝播する圧縮波のパッシブコントロール(S49-1 トンネルの空気力学と換気(1),S49 トンネルの空気力学と換気)  [in Japanese] 3626 Passive control of propagating pressure wave in a tunnel with a porous plate  [in Japanese]

A pressure wave is generated ahead of a high-speed train, while entering a tunnel. This pressure wave propagates to the tunnel exit and spouts as a micro pressure wave, which causes an exploding sound. From the fact that the ballast track tunnel has smaller noise than the slab track tunnel, we have suggested a new inner tunnel model called 'porous plate' to decrease the noise of the micro pressure wave, using the ballast effect. An experimental investigation is carried out to clarify the attenuation and distortion of the pressure wave while propagating.