Optimization of Train Nose Shape for Reducing Micro-pressure Wave Radiated from Tunnel Exit

摘要

When a compression wave generated by a high-speed train entering a tunnelnpropagates through the tunnel and arrives at the tunnel exit, an impulsivenpressure wave (micro-pressure wave) is radiated from the tunnel exit.nImproving the train nose shape is one of the techniques for suppressing thenmicro-pressure wave. Furthermore, tunnel entrance hoods are required for longnconcrete slab tunnels in order to suppress the micro-pressure wave. The effectnof the tunnel entrance hood on the compression wave generated by the train cannbe evaluated by means of a rapid computational scheme devised and validatednexperimentally by Howe et al. In this study, the optimal longitudinalndistribution of the cross-sectional area of the train nose shape was determinednby using the rapid computational scheme and a genetic algorithm. The effect ofnthe nose shape optimization was confirmed through experiments using scalenmodels.