Study On The Running Safety Of High-Speed Trains Under High Temperature And High Sand Concentration

When high-speed trains run on the line, it will span a variety of climatic characteristics. Especially the train going across the desert, it must face the challenge of high temperature and high sand concentration. On one side, the bad operating environment affects the ride comfort of high-speed trains. On the other side, it is also a danger to the operational safety of high-speed trains. So, it is very necessary to study the operation safety of trains under the condition of high temperature and high sand concentration.This paper uses the numerical simulation method to start the research. Based on the theory of computational fluid dynamics and vehicle system dynamics, three simulation models were established, including an aerodynamic model of train, a heat transfer model of equipment cabin, a vehicle multi-body system dynamic model. With these molds, we can get the conclusions as follows:1. When high-speed trains run in the sandstorm, the area of positive pressure on the head train becomes larger; the area of positive pressure on the tail train becomes smaller; the erosion effect of sand on head train was worst. If the wind angle is 0°, the total drag force of the train increased by about 6%. If the wind angle is 90°, the drag forces of head train and middle train become larger, the drag force of the tail train become smaller; the side forces of the head train, middle train, tail train increase and the lift forces of those decrease.2. When two high-speed trains pass each other in sandstorm, the maximum values of the positive pressure of the measuring points which are on the trains in the leeward side become larger than those in crosswind. The pressure waves of the measuring points which are on the trains of the windward side in the sandstorm are almost the.same with those in crosswind. The drag forces of head trains become larger and the drag forces of middle train change little. The side forces of trains in sandstorm become larger.3. This paper studies the security domain of the high-speed trains in sandstorm and in crosswind. Results show that the trains running in the sandstorm is more dangerous.4. The calculation results of the equipment cabin temperature field distribution show that:the effect of sand on heat transfer is tiny; the flow quantities of the fan in traction motor, cooling unit, condenser, don’t change with temperature.The conclusions of this paper can provide some help for the safe running of trains under sandstorm.