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不同阻塞比下真空管道磁浮交通气动热特性

Aerothermal Characteristics of Maglev Transportation in Evacuated Tube with Different Blocking Ratios

  • 摘要: 目前,高速铁路提速面临着轮轨粘着、空气阻力、气动噪声和横风失稳等挑战,将磁悬浮与封闭的低真空管道结合可以极大的突破地面轨道交通的速度极限。然而磁浮列车运行在管道内部,类似活塞运动,会使管道内部的流场更为复杂,气动热问题会更加显著。本文基于三维、定常、可压缩的雷诺平均Navier-Stokes方程和SST k-ω两方程湍流模型以及风洞模型中气流相对于列车运动的原理模拟了高速磁浮列车在管道中的运动。通过数值计算,探究了磁浮列车以1000 km/h速度运行在初始气压为0.1 atm的管道内,不同阻塞比对管道内气动热环境、列车气动力以及流场结构的影响。分析结果:随着阻塞比增加,总阻力增加,列车车身表面温升逐渐增大;在列车头部驻点处出现较高的温度,且头部的温度变化较大,列车尾部处于低温区,其表面的温度较低,列车表面的最低温度出现在尾部;在列车尾部出现了局部超音速区,产生较大的激波,该区域的气流温度会出现大幅降低,当气流通过激波后,温度又大幅上升。本文的分析结果可为真空管道磁浮交通在选取不同阻塞比时提供理论依据。

     

    Abstract: At present,the speeding up of high-speed railways faces challenges such as wheel-rail adhesion, aerodynamic drag,aerodynamic noise and crosswind instability.Combining maglev with the sealed low vacuum tube can greatly break through the speed limit of ground rail transit.However,the maglev train running inside the tube,like piston movement,will make the flow field inside the tube more complex,and aerodynamic heat problems will be more significant.Based on the 3-D,steady and compressible Reynolds-averaged Navier-Stokes equations and SST k-ω two-equation turbulence model as well as the wind tunnel model,the motion of a high-speed maglev train in a tube is simulated.Through numerical calculation,the influence of different blockage ratios on aerodynamic thermal environment,aerodynamic force and flow field structure of maglev train running at 1000 km/h in a tube with an initial pressure of 0.1 atm was investigated.The results show that the total resistance and the temperature rise of the train body surface increase gradually with the increase of blocking ratio.At the stagnation point of the head of the train,the temperature of the head is higher,and the temperature of the head varies greatly.At the tail of the train,the temperature of the surface is lower,and the lowest temperature of the surface of the train appears at the tail.A local supersonic zone appears at the tail of the train,resulting in a large shock wave.The temperature of the air flow in this area will be greatly reduced.When the air flow passes through the shock wave,the temperature will rise sharply again.The analysis results can provide a theoretical basis for selecting different blocking ratios of evacuated tube maglev transportation.

     

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