Research On High-speed Train Operation Safety In The Gust Environment

The train may cause derailment accidents when driving on railway under the effect of gust.The wind of natural environment usually fluctuate in average wind,the train can keep stable when driving in low wind environment.In short time,it will be appear greatly transient wind,which effect on the body of train and the aerodynamic loads will occur significant changes,thus leading to safety indicators change,when safety indicators surpass prescript safe value,it will be cause seriously traffic accident.First,establish high-speed train aerodynamics model and numerical simulation of high-speed train in the windless environment.To analyze characteristics of each cross-section flow field and the pressure distribution.Then researching aerodynamic characteristics of the train under gust,respectively analysis the pressure and velocity of three train cabins that given pressure variation of windward and leeward of head and tail trains by the effect of gust.Based on that,to studied the effect of aerodynamic loads by changing gust model and wind direction and the speed of train,to investigate the variation of the aerodynamic loads.The research results show that the aerodynamic performance of train in gust environment worse than windless,the flow around the train exhibited different states at different times,windward pressure is substantially positive while the leeward pressure is substantially negative expect tail train;When the speed of train is increased and the wind direction is altered,the aerodynamic loads of three train cabins variate more intense,when angle of wind direction between 60° and 90°,the variation of aerodynamic loads are much more outstanding than other angles.Through research the aerodynamic performance of the train at different gust model,the loads of three trains both have complicated variation trend;through comprehensive analysis,we may obtain that when the wind direction is 90°,the safety of each cabin is worst,where the loads variation of head train changes larger than middle train and tail train,therefore the safety of head train is worst.On based of simulation analysis of aerodynamic performance,establish system dynamics model of the head train,then calculate the safety indicators in different speeds and gusts as well as determining the security domain of the running speed of train.By analyzing the results,we may obtain that the safety indicators increase along with improving wind speed and train speed,determining the security domain of train:when the extreme speed of gust is 17.1m/s,allowing the maximum speed of High-speed train less than 300km/h,when the transient wind speed reached to 32.6m/s,allowing the speed of High-speed train less than 175km/h.