The Influence of Crosswinds on Dynamic Responses of High-Speed Train Exiting the Tunnel

The change of infrastructure scenarios from a tunnel to an open-air zone under crosswind causes severe aerodynamic loads on the high-speed train, which affects the running performance of it significantly. Focus on a tunnel under construction in a Chinese mountain railway, the running safety of the high-speed passing through the tunnel exit subject to crosswind is studied. An aerodynamic simulation model utilizing the finite volume method and overset mesh technique is established to investigate the aerodynamic characteristics of the train. A detailed three-dimensional numerical train-track coupled model considering derailment is further employed to study the effect of aerodynamic loads on the train dynamic performance. The results indicate that aerodynamic loads applied to the leading vehicle increase instantaneously when exiting the tunnel subject to crosswinds, especially the yawing moment. Compared with the case that the train exits a single-track tunnel, the aerodynamic loads change more quickly when the train enters the open-air from a double-track tunnel. The pressure difference at the nose part of the leading carriage is one of the main factors that contributes to the additional yawing moment. Additional aerodynamic loads aggravate the wheel-rail interaction, and the wheel-rail forces for the first wheelset change more severe than others.