摘要
随着经济发展和社会需求,研制更高时速的货运列车迫在眉睫.根据我国新研发的时速160公里的货运列车,需要开展货运列车通过隧道时的车体气动载荷研究.采用一维可压缩非定常不等熵流动模型特征线数值模拟隧道压力波方法,针对既有普速线的线路特点.研究高速货运列车单列车通过隧道的压力波形成机理和变化规律;研究不同工况下不同列车速度、车辆类型、隧道净空面积和隧道长度对最大正负压值和最大压力峰峰值的影响规律,归纳主要因素对车体气动载荷的影响规律及主次关系,获得货运列车车体强度设计和评估用气动载荷分布规律和范围.研究结果表明:单列车通过隧道时的压力波与列车驶入、驶出隧道诱发的压缩波和膨胀波反射和叠加相关;随着列车速度的提高、隧道净空面积的减小,列车车外最大正负压值和最大压力峰峰值均增加;在相同工况下,全侧开式棚车的的压力波动幅值大于塞拉式快捷车压力波动幅值;单列货运列车通过2.5 km隧道及以上时,最大正压值达到恒定值,最大负压值在最不利长度隧道处,达到最大值,然后随着隧道长度的增加逐渐减小;最大压力峰峰值在最不利长度隧道处达到最大值后随着隧道长度的增加而逐渐减小.本文研究结果可为货运车体气动疲劳强度设计提供支持.
With the economic development and social demands,it is urgent to develop freight trains of higher speeds.According to the newly developed freight train with the speed of 160 km/h,it is necessary to study the aerodynamic loads when it passing through the tunnel.The paper studies the formation mechanism and change rule of pressure waves in tunnels of freight train by numerically simulating the pressure waves with characteristics lines of one-dimensional unsteady compressible non-homentropic flow model.Influences of different speeds,freight train types,clearance areas,and tunnel length on the maximum positive,maximum negative and maximum peak to peak pressure value of tunnel pressure wave are analyzed.The influence law and primary and secondary relation of main factors on the pressure load of freight train body are summarized,and the distribution law and range of aerodynamic load used for strength design and evaluation of freight train body are obtained.The results shows that when the single-train travelling through tunnels,the pressure external the train is related to the reflection and superposition of compression wave and expansion wave induced by the train entering and leaving the tunnel.With the increase of train speed and the decrease of tunnel clearance areas,the maximum positive,maximum negative and maximum peak to peak value of the external the train pressure all increase.Under the same working condition,the pressure fluctuation amplitude of the full-side open box car is larger than that of the sierra express car.When a single freight train passes through a 2.5 km tunnel or above,the maximum positive pressure reaches a constant value,while the maximum negative pressure reaches a maximum value at the most unfavorable length of the tunnel,and then decreases gradually with the increase of the tunnel length.The peak-to-peak value of the maximum pressure decreases with the increase of the tunnel length after reaching the maximum value at the most unfavorable tunnel length.The findings of this study can provide support for the aerodynamic fatigue strength design of freight train body.
作者
魏康
周晓坤
梅元贵
WEI Kang;ZHOU Xiao-kun;MEI Yuan-gui(Gansu Province Engineering Laboratory of Rail Transit Mechanics Application,Lanzhou Jiaotong University,Lanzhou 730070,China;Dalian R&D Center of CRRC Qiqihar vehicle co.,LTD,Dalian 116052,Liaoning,China)
出处
《兰州交通大学学报》
CAS
2020年第6期65-72,共8页
Journal of Lanzhou Jiaotong University
基金
国家重点研发计划(2017YFB1201302-15)。
关键词
货运列车
隧道
气动载荷
一维可压缩非定常不等熵流动模型
freight train
tunnel
aerodynamic load
one-dimensional unsteady compressible non-homentropic flow mode
