Analysis and Modeling of Pressure Wave at the Entrance of the High-Speed Train to Tunnel

When a high-speed train enters into a tunnel, a pressure wave will be created. This leads to piston phenomenon in the tunnel, which affects all air currents in the tunnel. This phenomenon may lead to some problems in the long time like destruction of tunnel wall layers, safety of the passengers, ventilation of the subway stations and disturbing train balance. In this research, this phenomenon was investigated for entering of an ICE2 train to a single-line tunnel. Simulation is performed by using numerical solution in ANSYS Fluent CFD software considering sliding mesh, three-dimensional, incompressible and turbulent flow. The numerical method has been validated with an experimental test for the flow speed in the tunnel. Simulations have been done for 60, 80 and 100 m/s train speeds. Overal results showed that with increasing the train speed, the pressure domain and aerial wave speed will increase too. Finally, the strength of train’s front glass against maximum air wave has been studied and permissible train-speed range for entering the tunnel has been obtained.