Flow Simulation and Aerodynamic Noise Prediction for a High-Speed Train Wheelset
Flow Simulation and Aerodynamic Noise Prediction for a High-Speed Train Wheelset
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DOI：
10.1260/1475-472x.13.7-8.533
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发表时间：
2014-12
影响因子：
1
通讯作者：
Jianyue Zhu;Zhiwei Hu;David Thompson
中科院分区：
文献类型：
--
作者：
Jianyue Zhu;Zhiwei Hu;David Thompson
空气动力学噪声对于高速列车变得重要，并且在工业背景下难以实现其预测。本文采用计算流体力学和声学模拟的两阶段混合方法，以1：10的比例尺研究了高速列车轮对（转向架的主要部件之一）绕流的气动和声学特性。近场非定常流是通过延迟分离涡模拟数值求解Navier-Stokes方程得到的，其结果被馈送到使用Ffowcs Williams-Hawkings声学类比来预测远场噪声信号。在低噪声开放式消声风洞中测量了缩比模型的远场辐射声。音调噪声的主频和频谱形状的数值和实验结果之间取得了很好的一致性。结果表明，轮对湍流流动的特征是具有不同尺度和方向的三维流向涡和展向涡。轮对周围的旋涡脱落和流动分离是产生气动噪声的关键因素。研究发现，辐射的音调噪声对应于轮对的振荡升力和阻力的主导频率。辐射噪声的方向性表现出典型的偶极子模式。随着入流速度的增加，脱落频率与自由速度和轴直径成比例，以产生0.18的Strouhal数，而噪声水平显着增加。对于目前的轮对情况下，不考虑地面效应的调查，包括轮对旋转增加辐射噪声水平略有类似的方向性。
Aerodynamic noise becomes significant for high-speed trains and its prediction in an industrial context is hard to achieve. The aerodynamic and aeroacoustic behaviour of the flow past a high-speed train wheelset, one of the main components of a bogie, are investigated at a scale 1:10 using a two-stage hybrid method of computational fluid dynamics and acoustic analogy. The near-field unsteady flow is obtained by solving the Navier-Stokes equations numerically through delayed detached-eddy simulations and the results are fed to predict the far-field noise signals using the Ffowcs Williams-Hawkings acoustic analogy. Far-field sound radiated from the scaled model is also measured in a low noise open-jet anechoic wind tunnel. Good agreement is achieved between numerical and experimental results for the dominant frequency of tonal noise and the shape of the spectra. Results show that turbulent flow past the wheelset is characterized by three-dimensional streamwise and spanwise vortices with various scales and orientations. Vortex shedding and flow separation around the wheelset are the key factors for the aerodynamic noise generation. It is found that the radiated tonal noise corresponds to the dominant frequencies of the oscillating lift and drag forces from the wheelset. The directivity of the noise radiated exhibits a typical dipole pattern. As the inflow velocity increases, the shedding frequency scales with the freestream velocity and the axle diameter to yield a Strouhal number of 0.18 while the noise levels increase noticeably. For the current wheelset case investigated without considering the ground effect, the inclusion of wheelset rotation increases the radiated noise levels slightly with similar directivity.