| With the development of high-speed railway transport,the high-speed passenger transport demand of China has surged.The operation of double-deck high-speed EMU with greater passenger capacity can meet the growing travel demand of passengers and improve the efficiency of train transportation.The double-deck high-speed EMU has a high centre of gravity and a large windward area,so its operational safety is more significantly affected by crosswinds.This thesis takes a double-deck high-speed EMU as the research object,and conducts an profound study on the cross-wind running safety of the double-deck high-speed EMU train.Numerical simulation combined with wind tunnel test method is used to analyze the aerodynamic characteristics of double-deck high-speed EMUs under the different conditions.And the five-mass model method based on the European standard EN14067 is used to analyze the overturning stability of the double-deck high-speed EMU in the cross-wind environment,and the influence of different factors of the train on the cross-wind overturning stability of the train is discussed.The research contents and results of this thesis are as follows:(1)For a typical type of double-deck high-speed EMU in China,the aerodynamic simulation analysis model of three-section vehicle marshalling under cross-wind conditions is established,and the Fluent software is used for numerical simulation.The experimental data are in good agreement and meet the engineering needs,which verifies the validity of the model and the numerical calculation method.(2)Using the aerodynamic simulation model of the train,the aerodynamic characteristics of the train in the cross-wind environment were analyzed,and the aerodynamic loads on the train at different sideslip angles on flat ground,embankments and bridges with different heights were obtained.The results show that the aerodynamic load of the lead car is the most significant under the three different working conditions.The aerodynamic load of the lead car increases first and then decreases with the increase of the sideslip angle.In the case of flat ground,when the sideslip angle is 60° When the maximum value is obtained,the change trend of the embankment and bridge conditions is similar to that of the flat ground condition,but the aerodynamic load of the leading vehicle in the embankment condition is much greater than that of the flat ground condition.(3)Based on the MATLAB platform and the five-mass model method,the program was written for the analysis of the critical overturning wind speed of the train,and the correctness of the program and the applicability of the method were verified through calculation and comparison.Crosswind overturn safety studies.The results show that: in typical flat road conditions,when the cross wind is perpendicular to the direction of the train,the critical overturning wind speed of the train decreases with the increase of the speed of the train,and there is a significant change before and after the speed range of 60～80km/h.When the train speed is 300km/h/h,the corresponding critical overturning wind speed of the leading vehicle is 19.7m/s.Under the same vehicle speed,the critical overturning wind speed of the leading vehicle decreases with the increase of the wind direction angle,and the flat road condition reaches the lowest value when the wind direction angle is 90°.At the same time,the train operation and load status also have a significant impact on the crosswind safety of the train.(4)Double-deck high-speed EMUs operate under different road conditions,and their cross-wind safety varies greatly.Under the three road conditions of flat ground,embankment and bridge,the overturning wind speed of the embankment is the smallest,and the height of the embankment has a great influence on the stability of the train overturning in the crosswind.When the wind direction angle is 90°,in the case of10 m embankment,the critical overturning wind speed of the leading vehicle is 5～8m/s lower than that in the case of flat ground. |
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