2A23 Characteristics of the train wind for the train passing the tunnel and passing by each other in the tunnel(Boundary)
Details
Induced airflow from passing trains will generate the adverse impact to the environment or people near the train. Especially the aerodynamic forces on the human body generated by the high-speed train wind would endanger the safety of pedestrians or roadside workers. In addition to the scene that the train runs in the open air, the scene that the train passes by the tunnel or trains pass by each other in the tunnel also can generate strong train wind, which is also named as piston-wind. The train wind could deteriorate rapidly for the train passing the tunnel and trains passing by each other in the tunnel, compared to that generated by the train running in the open air. Consequently, the train wind could be an important issue for the running safety of the train in these scenes, and could also be a threat to the workers in the tunnel. In the present paper, the characteristics of train wind for the train passing by the tunnel and passing by each other in the tunnel is studied. Three-dimensional numerical simulation is performed, and the dynamic mesh technique is also utilized to simulate the passing process. Several speeds are investigated, which includes the speed of 160 km/h, 200 km/h, 250 km/h, 300 km/h and 350 km/h. Numerical results reveal that a linear relationship exists between the running speed of the train and the speed of the train wind for both scenes. For the train passing the tunnel, the maximum speed exists at the entrance of the tunnel, while the train wind in the middle of the tunnel keeps relatively constant. The speed of the train wind increases with the speed of the train with the slope of 0.097. For trains passing by each other in the tunnel, maximum speed exists both at the entrance and exit of the tunnel, while a relatively low speed for the train wind could be observed in the middle of the tunnel. The speed of the train wind increases with the speed of the train with the slope of 0.073.
