摘要
以一个椭圆形截面拱为工程背景,对其气动特性和共振风速进行了研究。首先,分别制作了该结构1∶150和1∶300缩尺比的测压与测力试验模型,研究了典型工况下的平均和脉动风压系数、平均气动力系数及Strouhal数等。其次,采用测力试验得到的三个坐标轴方向脉动基底力对应的峰值频率,对该结构的共振风速进行了估算。结果表明:该椭圆截面拱的气流分离点出现在圆周角112.5°附近,最小平均风压系数在0.9左右波动;脉动风压分布受气动外形影响较大,最大脉动风压系数发生在拱顶靠近观光平台的两侧截面气流分离点处,约为0.23;平均气动力系数在拱轴方向沿圆周关于180°风向角反对称,而在垂直于拱轴的方向呈正对称,最大平均阻力系数为0.42左右,远小于圆形截面值;结构三个坐标轴方向的脉动基底气动力功率谱均出现明显的能量峰值,且各峰值对应的频率不同;结构的第一阶振动以垂直于拱轴方向的振动为主,共振风速为38.8 m/s。
Taking an arch structure with elliptic cross section as engineering background,the aerodynamic features and resonance wind velocity of this structure were investigated in detail.First,two types of test models,one with a geometrical scale of 1∶150 for pressure measurement and the other 1∶300 for force measurement,were both made,and a series of pressure and force measurements wind tunnel tests were carried out.The mean and fluctuating wind pressure coefficients,the mean wind force coefficient and the Strouhal number under typical case were obtained.Then,the resonance wind velocity of this structure was estimated by using the Strouhal number obtained in this paper.The results show that the mean drag coefficient of the arch with elliptic cross section(about 0.4)is far smaller than the value for the circular cylinders(about 1.2).Obvious energy peaks are found in the power spectrum densities of the fluctuating base forces in three directions,and the Strouhal number are all smaller than the value for the circular cylinders.The first model vibration of the structure is dominated by the vibration perpendicular to the arch axis,and the resonance vibration velocity is about 38.8 m/s.
作者
张念林
王君鹏
杨斌
Zhang Nianlin;Wang Junpeng;Yang Bin(Shandong Electric Power Engineering Consulting Institute Co.,Ltd.,Jinan Shandong 250013,China)
出处
《山西建筑》
2024年第11期51-54,共4页
Shanxi Architecture
关键词
椭圆形截面
气动力
拱
Strouhal数
共振风速
elliptic cross section
aerodynamic forces
arch
strouhal number
resonance wind velocity
