Numerical Simulation for Propagation of Pressure Waves in Railway Tunnels

When a high speed train, such as bullet train, passes through a tunnel, pressure fluctuations act on the body because of the propagation of pressure waves generated by the train entering a tunnel. In this report, a numerical analysis method for unsteady one-dimensional compressible flow, in which the method of characteristics is employed, is presented. A computer program using this method was used to investigate the propagation of pressure waves and pressure fluctuations. Calculations are performed with a train velocity of 300km/h. Results of pressure profiles in a tunnel, profiles of the rate of change of pressure, and pressure histories at front and rear sections of the train are presented.