基于双向流固耦合的无拉索天线桅杆风致振动特性研究  

Wind-induced Vibration Characteristics of Cable-free Antenna Mast Based on Bidirectional Fluid-structure Interaction

作　　者：杨雨春 王杰[1] 胡凯 YANG Yuchun;WANG Jie;HU Kai(School of Mechanical Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学机械工程学院,四川成都610065

出　　处：《机械》2024年第1期9-16,23,共9页Machinery

摘　　要：为研究正六边形无拉索天线桅杆的风致振动特性,本文进行了基于双向流固耦合的数值模拟研究。建立了无拉索天线桅杆固体网格及外流场重叠网格三维有限元模型,利用ANSYS Workbench搭建基于Transient、Fluent和System Coupling的双向流固耦合仿真系统,对不同风速下桅杆的横向、顺风向振动位移及受力进行了分析,并运用Model模块计算了桅杆前六阶固有频率及其对应模态。结果表明:无拉索天线桅杆在风速U=13.5 m/s时会发生振动形式转变,振动形式从第一阶模态转变为第一阶与第二阶混合模态,横向振幅在此风速下出现极小值;桅杆受到的顺风向阻力数值模拟结果与经验公式基本相符,对比误差不超过8.5%;无拉索天线桅杆尾流主涡的交替摆动是其受到脉动横向风载的主要原因。A numerical simulation based on bidirectional fluid-structure interaction is carried out to study the wind-induced vibration characteristics of regular hexagonal cable-free antenna mast.In this paper,we established a three-dimensional finite element model of the solid mesh and external flow field overlapping mesh of the cable-free antenna mast.ANSYS Workbench is used to build a bidirectional fluid-structure interaction simulation system based on Transient,Fluent and System Coupling.The simulation system is used to analyze the lateral and downwind vibration displacement and force of the mast at different wind speeds,and the natural frequencies of the first six orders of the mast and their corresponding modes are calculated by using the Model module.The results show that the cable-free antenna mast will undergo vibration form transformation at the wind speed of U=13.5 m/s,and the vibration form will change from the first-order mode to the first-order and second-order mixed mode.The lateral amplitude will be extremely small at this wind speed.The numerical simulation results of downwind resistance of the mast are basically consistent with the empirical formula,and the comparison error does not exceed 8.5%.The alternating oscillation of the main vortex of the wake of the cable-free antenna mast is the main reason for its pulsating lateral wind load.

关 键 词：无拉索天线桅杆 双向流固耦合 固有频率 风致振动 

分 类 号：TH13[机械工程—机械制造及自动化]