Passive Control of Micro-Pressure Wave from High-Speed Railway Tunnel

When a high-speed train enters a tunnel, a compression wave is generated ahead of the train and propagates along the tunnel. This wave subsequently emerges from the exit portal of the tunnel as a micro pressure wave which may cause an impulsive noise problems in the surrounding area. The objective of this paper is to show the optimum silencer to reduce an impulsive noise. The effects of the exit boxes at the circular tube exit on the impulsive noise were investigated numerically. As a result, the optimum location of an exit box are found and the noise alleviative rate have been clarified.