张伟峰, 张志田, 张显雄. 桥梁断面气动导纳风场依赖特性的数值研究[J]. 空气动力学学报, 2018, 36(4): 677-686, 694. DOI: 10.7638/kqdlxxb-2016.0067
引用本文: 张伟峰, 张志田, 张显雄. 桥梁断面气动导纳风场依赖特性的数值研究[J]. 空气动力学学报, 2018, 36(4): 677-686, 694. DOI: 10.7638/kqdlxxb-2016.0067
ZHANG Weifeng, ZHANG Zhitian, ZHANG Xianxiong. Numerical investigation on the wind-field-dependence property of bridge section aerodynamic admittances[J]. ACTA AERODYNAMICA SINICA, 2018, 36(4): 677-686, 694. DOI: 10.7638/kqdlxxb-2016.0067
Citation: ZHANG Weifeng, ZHANG Zhitian, ZHANG Xianxiong. Numerical investigation on the wind-field-dependence property of bridge section aerodynamic admittances[J]. ACTA AERODYNAMICA SINICA, 2018, 36(4): 677-686, 694. DOI: 10.7638/kqdlxxb-2016.0067

桥梁断面气动导纳风场依赖特性的数值研究

Numerical investigation on the wind-field-dependence property of bridge section aerodynamic admittances

  • 摘要: 基于二维不可压非定常RANS模型,分别计算了平板断面、箱梁断面、双边肋断面在简谐脉动来流和宽频湍流中的非定常气动力,并识别出各自的气动导纳函数。在此基础上,通过考察断面在三种不同脉动幅值来流作用下的气动导纳,研究了不同脉动幅值对各类断面气动导纳的影响。结果表明,在竖向简谐脉动来流下,平板断面的气动导纳与Sears函数吻合良好,证明数值识别气动导纳的可行性;湍流作用下,平板断面识别的导纳函数有着实质性的不同,表现出很强的随机跳跃性。与平板断面类似,箱梁断面的气动导纳接近Sears函数。在不同幅值的简谐脉动来流下,平板断面和流线型箱梁断面识别的气动导纳基本一致,表现出了流线型断面对来流特性的不敏感性。计算结果表明,具有显著分离流的双边肋断面,其气动导纳具有明显的来流风场依赖性,表明钝体断面的气动导纳并不能定性为断面的函数,而是由断面与来流风场特性共同确定。

     

    Abstract: Based on two-dimensional incompressible, unsteady Reynolds averaged Navier-Stokes (URANS) numerical models, aerodynamic admittances of a thin plate, a box-girder section, and a double-girder section are numerically identified. Two types of oncoming flow are considered in the simulations. One is harmonic fluctuating flow, and the other is broadband turbulent flow. Furthermore, the influences of the amplitude of the harmonic flow on the aerodynamic admittances are investigated. Numerical results indicate that, for the case of thin plate, aerodynamic admittance functions obtained from the harmonic flow are in good agreement with the Sears function. This agreement indicates the reliability of the adopted numerical model. With the oncoming turbulent flow, however, the obtained admittance functions substantially differ from those from harmonic wind fields, and exhibit strong stochastic property. Similar to those of the flat plate, the admittances of the box girder section is close to the Sears function. For the flat plate and box girder sections, their admittances from harmonic flows of different amplitudes are basically in accord with each other, showing the insensitivity to the oncoming wind field. However, the results show that the admittance functions of the double-girder section, which is characterized by severe flow separations, exhibit strong dependence on the approaching wind field. This indicates that, for bluff body sections, aerodynamic admittances could not be taken as a function of the sectional configuration only, but rather, a function jointly determined by the configuration and the wind properties.

     

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