Aerodynamic Response Analysis of High-Speed Trains Passing through High Platforms under Crosswind

Abstract

At stations, high-speed trains frequently pass through the platform without stopping, where a combination of two island platforms represents the most common layout. The interaction between the train and the platform leads to certain problems, such as reductions in the comfort of the waiting environment and the safety of people around the platform. However, in the literature, there are few studies on the aerodynamic response between the train and the platform and on the airflow field characteristics above the platform when the train passes through the platform under different crosswind speeds. Therefore, we attempted to fill this gap using numerical methods to study the aerodynamic characteristics of the train passing through island platforms at 350 km/h under different crosswind speeds (10, 15, 20, 25, and 30 m/s). The aerodynamic response of high-speed trains combined with the flow field distribution is discussed in depth. We studied the wind speed distribution at different longitudinal distances above the platform, and obtained the position of the maximum wind speed when the head and tail car passed through the platform. Based on this, the wind speed distribution at different lateral distances above the platform was studied, and the reasons for the airflow changes above the platform were analyzed. The research results show that when a train enters a platform at 350km/h under a crosswind speed of 30 m/s, the reductions in the drag and lateral force of the whole vehicle reach their maximum, which are 50.44% and 66.51%, respectively. However, the change trend in the whole car lift force is opposite to that of the drag and lateral force, which increase when the train enters the platform and decrease when it leaves the platform. The largest growth in lift force is 102.39%, which occurred at a wind speed of 30m/s. The airflow velocity above the platform will increase rapidly as the head and tail car pass through the platform. A higher crosswind speed will result in the monitoring point of platform reaching its maximum airflow speed to an earlier time as the tail car passes through the platform. Meanwhile, we found that the lateral distance 1 – 2m above the platform is the area with the largest wind speed attenuation.