Dynamic Performances Of High-Speed Trains Passing Each Other

The aerodynamics of two trains passing each other is one of the important aspects on the safety and comfort of trains. Researching the forming causation of train aerodynamic performances and vehicle dynamic characteristics of high-speed trains passing each other is significant to the fast and security running of trains. Finding out how train speed, environment crosswind speed and lines environment influencing the dynamic performances of trains passing each other is also important.Based on the aerodynamic and vehicle dynamics, the train aerodynamic model and vehicle dynamic model are established, respectively, in this paper. Then by the simulation of the train aerodynamic model and vehicle dynamic model with the computational software FLUENT and SIMPACK, the pressure waves and aerodynamic forces and vehicle dynamic responses are obtained. The pressure distribution, pressure waves and aerodynamic forces of the trains passing each other are concerned on the sudy of train aerodymaic performances. And the security indexes (coefficient of derailment, wheel unloading rate, the wheelset lateral force and the wheel-rail vertical force), comfort indexes (the lateral acceleration and the vertical acceleration) are concerned on the study of the vehicle dynamic characteristics. The content of studying on the trains passing each other includes the following aspects in this paper:1. The basic aerodynamic performance and vehicle dynamic characteristics are studied without crosswind environment, and the relationship between dynamic responses and train speed is obtained.2. The train aerodynamic performance and vehicle dynamic characteristics are little influenced by different lines (ground, embankment and bridge) in the open air without crosswind environment.3. The rationality of track spacing5.0m is proved to the train passing each other at the speed of350km/h and380km/h. Then, analyzing the influences to the train dynamic perfrormances by the track spacing, the suggested track spacings are proposed for the higher-speed train.4. The relationship among train dynamic performances, track spacing and length of the stream-lined nose is studied at the speed of450km/h. Then the suggested length of the stream-lined nose is proposed for the train passing each other at the speed of450km/h on the5.0m track spacing.5. By studying of the wind field distribution in different lines (ground, embankment and bridge) with different speed level of the index crosswind, the relationship between the wind speed of monitoring position and entry position. In addition, the constant crosswind and boundary friction coefficient are considered.6. The train aerodynamic performances and vehicle dynamic characteristics of trains passing each other under crosswind environment are researched on different lines (ground, embankment and bridge), considering wind angle, wind speed and train speed factors.7. The dynamic performances of two trains passing each other under crosswind on different lines (ground, embankment and bridge) are compared and analysed and dynamic performances of the leeward train are worse. According to the study on the security domain of leeward train on different lines, safety on the embankment is the worst, the last of the bridge, on ground relatively safe.