PRESSURE WAVE-PROPAGATION IN A SHORT TUNNEL CAUSED BY PASSING TRAINS

The aerodynamic behaviour of pressure transients in railway tunnels du e to the passage of train are accompanied by the wave reflection betwe en the entrance and exit of the tunnel as well as the tunnel wall and train surface. This study presents a numerical method using the Harten -Yee upwind TVD scheme to simulate compression wave transients and ref lection in a railway tunnel. The strength of the compression wave gene rated by the entrance of a train into a tunnel emerged within the appl ied calculation procedure, without any special consideration of the bo undary condition for the entrance or exit of the tunnel as well as the train noise and tail. Good agreements were obtained when the initial pressure rise at tunnel entrance and the process of pressure variation s in a short tunnel, which were calculated by the presented numerical method, were compared experimental data. The pressure wave reflection at the entrance and exit, the unsteady flow around the train and the t ransmitted wave at tunnel exit portal were simulated. The transmitted wave at the tunnel exit portal is also discussed. In addition, a metho d to determine the non-reflective boundary condition for multi-dimensi onal Euler equation is given.