Aerodynamic Behavior And Dynamics On High-speed Trains Passing With Each Other

With the increasing of train speed, the aerodynamic problem plays an increasing prominent role on running train, especially when the high-speed train pass through tunnels, or two trains meet in open air as well as in tunnels, which may cause a strong disturbance to the ambient air, i.e., transient pressure wave. Such transient pressure wave may break the window glass of the train, even more, it could cause passengers’ tinnitus and other uncomfortable symptoms. In addition,the vehicle will rollover or derail because of the lateral and vertical vibration and the hunting motion’s increasement caused by the aerodynamic force and moment. The dynamic response by the aerodynamic force and moment has a terrible influence on safety and stationarity of the vehicle.Based on 3D time Reynolds average Navier-Stokes equations of viscous compressible fluid, and the turbulent model of k -e two equations, the aerodynamics effects when two trains meeting with each other in open air and tunnel and one single train passing through a tunnel is studied by means of CFD including the sliding mesh methods. The laws of the pressure on the train surface are analyzed according to the data collected by monitor points. The amplitude of pressure is studied in different train speed as well as track distance. Considering different situations, the pressure on the train surface is compared. Finally, the aerodynamic force and moment which have an effect on the train are obtained by CFD. The laws of the aerodynamic force and moment are also compared and analyzed.Furthermore, the vehicle dynamic behavior subject to the aerodynamic force and moment are studied based on the vehicle dynamic model established by Simpack. For the three cases which are the train passing through a tunnel, meeting in the open air as well as in the tunnel, the acceleration of the train are analyzed respectively. According to the acceleration, the derailment coefficient and sperling value are obtained in different speed and track distance. Finally, the safety and stationarity of the vehicle are compared and evaluated among different situations.