真空管道高速列车气动噪声研究

为了探究真空管道高速列车气动噪声随着列车运行马赫数变化的分布规律,本文对真空管道交通(VTT)系统内高速列车气动噪声的研究主要采用理论研究和数值模拟相结合的方法。采用基于Lighthill声学分析法,建立高速列车的二维模型。运用流体软件FLUENT进行数值模拟,数值计算并分析了低压环境下真空管道内高速列车远场气动噪声的分布规律、频谱特性以及声压等声学指标;然后通过对数值模计算结果的后处理,对气动噪声数值规律总结。结果表明气流流速快、扰动作用强、脉动压力大、湍流活动剧烈的流线型车头为高速列车主要的噪声声源,即列车的气动噪声取决于列车表面脉动压力,脉动压力越强,声压值越大。

Aerodynamic Noises of Vacuum Tube Transportation: A Simulation and Theoretical Study

The fluid fields,around the high-speed train running at different Mach numbers in vacuum tube transportation(VTT),were empirically approximated,mathematically modeled on the basis of Lighthill acoustic analysis scheme,theoretically analyzed and numerically simulated in finite element method with software FLUENT.The distribution,spectral characteristics and acoustic pressure of the far-field aerodynamic noises,generated by the high-speed trains travelling in the vacuum tube,were calculated.The simulated results show that the streamlined train-head is the main source of noises,because it generates fast airflow,strong disturbance,high pulsation pressure and violent turbulence; that is,the pulsation pressure on the surfaces of train-head makes the strongest aerodynamic noises.