超高输电铁塔的气动噪声特性研究

Study on the Aerodynamic Noise Characteristics of Ultra-high Electricity Transmission Tower

超高输电铁塔在保障居民日常生活和工业生产中起到了重要作用,由于极高的高度,其在风荷载作用下产生的气动噪声问题不容忽视。本文针对超高输电铁塔气动噪声扰民的问题,建立了其计算流体力学(Computational Fluid Dynamics,CFD)计算模型,采用标准k-ε湍流方程进行稳态初场的计算,并在此基础上采用大涡模拟方法与声类比方法进行瞬态流场计算及气动噪声计算,分析流场的流动特性及气动噪声特性。结果表明,4根主纵梁以及电梯井的左右两侧具有强烈的压力脉动,是主要的气动噪声源,其最大值出现在电梯井顶端区域;各虚拟测点的总声压级沿高度先增加后减小,总声压级沿高度的变化由风速与输电铁塔自身结构尺度参数共同控制;通过声成像测量方法确定了声源的在塔身中部以上、横担以下的位置,验证了仿真结果的正确性;声压级与风速的峰值出现的时刻基本吻合,输电铁塔风致噪声与风速存在着强相关性。本文的研究结论对于超高输电塔气动噪声特性的研究和输电塔的降噪设计具有指导意义。

The ultra-high electricity transmission tower plays an important role in ensuring the daily life of residents and industrial production.Due to its extremely high height,the aerodynamic noise problem caused by wind cannot be ignored.In this paper,the CFD(Computational Fluid Dynamics)simulation model is established to solve the problem of disturbing residents caused by aerodynamic noise of ultra-high electricity transmission tower.The standard k-εturbulent equation is used to calculate the initial steady flow field,and the large eddy simulation method and FW-H acoustic analogy method are respectively used to calculate the transient flow field and aerodynamic noise.With the obtained results,the wind flow around the tower and aerodynamic noise characteristics of the flow field are analyzed.The results show that the left and right sides of four main longitudinal beams and the elevator shaft have strong pressure pulsations,which are the main sound sources.The maximum value appears in the top area of the elevator shaft.The total sound pressure level of each measuring point increases first and then decreases along the height,and the change of the total sound pressure level along the height is jointly controlled by the wind speed and the tower structures′geometric parameters.The position of the sound source above the middle of the tower and below the cross arm,which is obtained through CFD and aeroacoustics simulations,is verified by acoustic imaging.Furthermore,there is a strong correlation between the noise caused by the wind flow around the tower and the wind speed.The research on aerodynamic noise characteristics of ultra-high electricity transmission tower presented in this paper has practical significance for the noise reduction design of the transmission tower.