Numerical study on high speed train and tunnel hood interaction

This paper reports numerical computations of the train–tunnel interaction at a tunnel entrance with real dimensions. Simulations were carried out by the FEM using the three-dimensional compressible Euler equation. The train speed was 300 km/h. For a single-track tunnel, four kinds of tunnel entrance shapes were studied to investigate the formation of the compression wave front at the tunnel entrance. This study shows the possibility of a partial change in the compression wave front by means of the optimal combination of the degree of the tunnel entrance slopes and holes in the tunnel entrance ceiling. The results can be used for countermeasures against the boom noise at the tunnel exit, for the air tightness design of the train body shell and fatigue damage of the tunnel wall and structure. The compression wave fronts at the tunnel entrance directly affected the pressure drop in the tunnel and the booming noise intensity at the tunnel exit.