3625 圧縮波の伝播・放射に及ぼすトンネル内高温度領域の影響(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] 3625 Effect of High Temperature Region in Tunnel on Propagation and Radiation of Compression Wave  [in Japanese]

An impulsive pressure wave radiating from a tunnel exit, which is called a micro-pressure wave, is one of the important environmental problems in high-speed railways. In this study, the propagation and radiation characteristics of compression wave have been studied numerically to show the effect of high and/or low temperature regions in tunnel near the exit on the radiated pulse. The result shows that the peak values of the radiated pulse have the similar properties with the corresponding rectangular compression wave of same leading portion. The local high-temperature region in addition with the low one can be effective for the reduction of radiated pulse and the same difference in temperature at the local region yields the similar reduction even for the different ambient temperatures.