摘要
研究真空管道列车瞬态气动特性能为建设多态耦合真空管道列车实验平台提供参考。建立了三维真空管道列车模型,采用剪切应力运输(Shear Stress Transport,SST)k–ω湍流模型求解流场,通过对比不同时刻列车匀速和加速时的气动阻力、压力分布及流场特性,揭示了加速度对真空管道列车气动阻力的影响机制。研究结果表明:头车和尾车气动阻力主要受管道壅塞和尾部激波脱离的影响,在非壅塞状态下,尾车阻力增长缓慢而头车阻力基本不变。相比于加速工况,匀速工况启动速度较大,斜激波反射造成列车表面压力波动,波动幅值随时间逐渐降低。加速时头车压缩前方空气过程较缓慢,前驱激波强度较低,头车气动阻力和周围压力的变化滞后于列车运行速度的变化,且加速度越小滞后效果越明显。在匀速运行阶段,壅塞段和尾部激波段长度与运行时间成正比。
The research on aerodynamic characteristics of the evacuated tube train provides a reference for the construction of ETT(Evacuated Tube Train)test platform.A 3-dimensional model was established,and the SST k–ωmodel was used to solve the flow field.The aerodynamic resistance,pressure distribution and flow field characteristics under constant speed and acceleration conditions were compared,and the influence mechanism of acceleration on the aerodynamic resistance was revealed.The results show that the aerodynamic drag of the head car and the tail car is mainly affected by the choked flow and the detach of the tail shock.In no-choked state,the drag of the tail car increases slowly while that of the head car is unchanged.Compared with the acceleration condition,the reflection of the oblique shock caused by the large starting speed leads to the pressure fluctuation on the train surface,and the amplitude of the fluctuation gradually decreaseswith time.As the head car compresses the front air slowly and the precursor shock wave is weak under the acceleration condition,the changes of the aerodynamic resistance and surrounding pressure of the head car lags behind that of the running speed,and the smaller the acceleration is,the more obvious the lagging effect is.In the stage of uniform speed,the length of the choked section and the tail shock is proportional to the operation time.
作者
宋嘉源
李田
张继业
SONG Jiayuan;LI Tian;ZHANG Jiye(State Key Laboratory of Traction Power,Southwest Jiaotong University,Chengdu 610031,China)
出处
《实验流体力学》
CAS
CSCD
北大核心
2023年第1期64-71,共8页
Journal of Experiments in Fluid Mechanics
基金
国家自然科学基金(12172308,52078433)
中央高校基本科研业务费(2682021ZTPY124)。
关键词
真空管道列车
瞬态
加速度
气动阻力
压力分布
流场特性
evacuated tube train
transient
acceleration
aerodynamic drag
pressure distribution
flow field characteristics
