轨道结构对真空管道磁浮列车气动特性的影响

The effect of track structure on the aerodynamic characteristics of evacuated tube maglev train

真空管道磁浮交通的出现使得地面超高速轨道交通成为可能。真空管道磁浮研究受限于对大功率推进电机和真空环境的需求,难以取得相关试验数据。针对多态耦合轨道交通动模型试验平台永磁轨道和电机气动布局的前期设计,本文开展了相关数值模拟研究。基于动模型试验平台几何结构、电机平台和永磁轨道在管道内的实际布置形式,采用三维、可压缩的RANS方法和SST k–ω湍流模型,计算了超导磁浮列车在真空管道内超高速运行时的三维流场结构、激波反射和传播规律,对比分析了列车底部矩形槽道对列车气动载荷和管道内流场的影响,重点探究了列车底部压力和速度变化趋势、尾部激波强度和尾涡结构的差异。研究发现:轨道和电机平台的台阶使得尾流区产生了更多的流动分离和激波反射,导致尾部压力波动;列车底部流动间隙增大,列车尾部激波强度下降,激波现象更为明显,气动阻力系数减小8.855%,气动升力系数增大14.312%。

The emergence of evacuated tube maglev transportation makes it possible for ground ultra-high-speed rail transit.However,limited by the demand for high-power propulsion motors and low vacuum environment,it is difficult to carry out experimental research.In this paper,the numerical research on the aerodynamic layout of the magnetic track and motor is carried out in the preliminary design of the Dynamic Model Test Platform for Multistate Coupled Rail Transit.Based on the geometric structure of the dynamic model test platform,considering the actual arrangement of the motor platform and the permanent magnet track in the tube,the three-dimensional,compressible RANS method and SST k–ωturbulence model are used to calculate the three-dimensional flow field structure and the shock wave reflection,propagation law of the superconducting maglev train in the low-pressure tube at ultra-high speed.The influence of the rectangular channel on the aerodynamic loads of the train and the flow field in the tube is compared and analyzed.The differences of the pressure and velocity change trend at the bottom of the train,and the shock wave strength at the tail and the wake structure are mainly explored.It is found that the step of the magnetic track and the motor can cause more flow separation and shock reflection in the wake region,resulting in tail pressure fluctuations.When the rectangular channel exists,the shock wave intensity at the tail of the train decreases,the shock wave phenomenon is more obvious,the aerodynamic drag coefficient decreases by 8.855%,and the aerodynamic lift coefficient increases by 14.312%.The research results can provide reference for the design of the magnetic track and motor platform of the multi-state coupling rail transit dynamic model test platform.