下击暴流作用下高速列车运行安全性能评估

EVALUATING THE SAFETY OF HIGH-SPEED TRAINS AT THE ACTION OF DOWNBURST

建立了一套利用物理模拟器的下击暴流作用下高速列车运行安全性评估方法。结果表明:受下击暴流风速场与气压场的共同影响,列车距下击暴流中心不同相对位置,所受气动力作用机制明显不同;下击暴流作用下,侧力对轮轨横向力贡献最大,侧滚力矩对轮轨垂向力贡献最大;轮对横向力、脱轨系数、轮重减载率等列车安全运行评价指标随径向距离的增大先增大后减小,相对径向距离r/Djet=0.83时(Djet为喷口直径),为列车安全运行的最不利径向位置;列车安全运行指标随风速、车速的增大而增大,列车安全运行的下击暴流临界风速值随车速的增大而急剧减小。

A set of safety evaluation methods of high-speed trains under the action of downburst are established by using physical simulator.The results show that under the combined effects of wind speed field and pressure field of downburst,the wind load acting mechanism is significantly different for each relative position of the train distance from the downburst center.Under the action of downburst,the side force contributes the most to the wheel rail lateral force,and the overturning moment contributes the most to the wheel rail vertical force.The evaluation index for the safe operation of trains such as transverse force,derailment coefficient,wheel unloading rate first increase and then decrease as the radial distance increases.The relative radial distance of r/Djet=0.83(Djet denotes nozzle diameter)is the most unfavorable radial position for the safe operation of trains.The train safety operation indicators increase with the increase of wind speed and vehicle speed,and the critical wind speed of downburst for safe train operation decreases sharply with the increases of vehicle speed.