谐振腔结构减缓高速磁浮列车隧道出口微气压波研究

Mitigation of micro-pressure wave at high-speed maglev tunnel exit by resonant cavity structure

  • 摘要: 在高速磁浮列车通过隧道过程中,受隧道内壁面和车体表面形成的环状空间限制,列车头部前方气流受到压缩,在隧道入口形成初始压缩波。初始压缩波在隧道内以当地声速传播至隧道另一端出口,部分能量以脉冲形式向外辐射,形成微气压波,严重影响隧道出口附近环境。当高速磁浮列车速度达到600 km/h以上时,这一问题更加显著。为此,提出一种具有谐振腔结构的隧道,采用三维、非定常、可压缩N–S方程和SST kω湍流模型研究其对高速磁浮列车通过隧道的气动效应减缓特性,并对2种谐振腔方案的减缓效果进行了数值模拟和动模型试验验证。研究结果表明:在隧道内冗余空间安装谐振腔结构,可以耗散压缩波能量,减小压缩波压力梯度,对隧道出口微气压波现象有明显减缓作用;与无谐振腔结构的隧道相比,谐振腔结构对隧道出口20和50 m处微气压波的减缓效果分别为41.87%和40.15%;微气压波减缓效果与隧道内谐振腔数量成线性关系;动模型试验进一步验证了数值模拟方法优选方案的准确性,不同速度试验结果表明微气压波减缓效果与运行速度正相关。

     

    Abstract: During the passage of the high-speed maglev train through the tunnel, the air flow in front is compressed due to the limitation of annular space formed by the inner wall of the tunnel and the surface of the car body, forming an initial compression wave. The initial compression wave propagates to the tunnel portal at the local sound speed, and some of it radiates outward to form a micro-pressure wave, which seriously affects the tunnel portal environment. This problem is even more pronounced when high-speed maglev trains reach speeds of 600 km/h. Therefore, a tunnel with a resonant cavity structure is proposed, and the three-dimensional, unsteady, compressible N–S equation and SST kω turbulence model are used to study the aerodynamic effect mitigation characteristics of the maglev train passing through the tunnel at high speed. The simulation comparison and dynamic model test verification of different resonator schemes are carried out. The results show that the resonant cavity structure installed in the redundant space in the tunnel can dissipate the compressed wave energy, reduce the rate of pressure change of the compression wave, and have a significant slowing effect on the micro-pressure wave at the tunnel opening. Compared with the existing tunnel, the resonator structure has a micro-pressure wave mitigation effect of 41.87% and 40.05% at 20 m and 50 m to the tunnel portal, respectively. The micro-pressure wave mitigation effect is linearly related to the number of resonators in the tunnel. The results of the moving model test show that the slowdown effect of the micro-pressure wave is positively correlated with the operating speed.

     

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