Effect of Expansion Wave Generated by Train Tail Entering into Tunnel on Lateral Vibration of High-Speed Train

抄録

It is well known that the lateral vibration of the trains running in tunnel becomes larger than that at open section, where we cannot find strong relevance to track irregularity in contrast to the vibration at open section. This vibration has been explained mainly by the aerodynamic flow separation and vortex shedding from the surface of trains. In this paper we focus on lateral vibration of the high-speed train (Shinkansen), and try to investigate not only flow separation but also expansion wave effect from the tail part of the trains on the vibration when they enter the tunnel. We have started to investigate with compressible and two-dimensional numerical analysis of aerodynamic flows around the trains. For the trains entering the tunnel, we performed the CFD with ghost cells and level set functions. As a result of interference of expansion waves and aerodynamic flow separation and alternating periodical expansion waves passing the train sides, large pressure difference on both sides of the trains moving forwards from the tail to the top is raised, which causes the lateral vibration.