Numerical investigation of three-dimensional compressible flows induced by a train moving into a tunnel (Q1373143)

A three-dimensional flow induced by a practical high-speed train moving into a tunnel is studied by the computation of the compressible Navier-Stokes equations with the zonal method. The transient flow field induced by tunnel entry is investigated with the focus on the compression wave which is the source of the booming noise at the tunnel exit. The results reveal a pressure increase inside the tunnel before tunnel entry, the one-dimensionality of the compression wave, the histories of the aerodynamic forces, etc. The computed pressure histories inside the tunnel agree with the field measurement data. The flow fields are also computed for cases where the train runs on differently positioned tracks into the tunnel.