Flow-induced vibration of a flexible cylinder placed in the wake of a stationary rigid cylinder is studied, experimentally. The flexible cylinder with an aspect ratio of 47 and a mass ratio of 120 was held fixed at both ends and placed horizontally in the wake of the upstream rigid cylinder in the test-section of a subsonic wind tunnel. The dynamic response of the cylinder is studied in both the streamwise (inline) and transverse (crossflow) directions for center-to-center spacing range from 3 to 9 times the diameter of the cylinder. Amplitudes and frequencies of oscillation, as well as flow forces on the cylinder are studied in the reduced velocity range of $U^{\ast }=3.3-50.3$ and the Reynolds number range of $Re=3,057$–46,536. The dynamic response observed in this study are presumably the result of two combined phenomena of vortex-induced vibration and wake-interference galloping. Despite the high-mass ratio of the flexible cylinder, higher modes of vibrations up to the fifth mode are excited in both the crossflow and inline directions, owing to the high-flexibility of the cylinder. Both odd and even modes are excited in the crossflow and inline directions. As the separation distance between the cylinders increases, the amplitudes of oscillation increase over a wider range of reduced velocities. Spanwise trajectories of motion are studied and regions along the length of the cylinder that are excited or damped by the flow, i.e., regions with positive and negative flow force coefficient in phase with velocity, are identified.

实验研究了放置在固定刚性圆柱体尾部的柔性圆柱体的流致振动。将纵横比为47，质量比为120的柔性圆柱体两端固定，并水平放置在亚音速风洞测试段中上游刚性圆柱体的尾部。研究了圆柱体在流向（直列）和横向（错流）方向上的动态响应，其中心到中心的间距为圆柱体直径的3到9倍。在减小的速度范围内研究了振荡的振幅和频率以及气缸上的流力。${ü}^{\ast }=3。3-50。3$ 和雷诺数范围 $\mathrm{[R}Ë=3，057$–46,536。在这项研究中观察到的动态响应大概是涡流诱发的振动和尾波干扰疾驰的两种组合现象的结果。尽管柔性圆柱体具有高质量比，但由于圆柱体的高柔韧性，在横流方向和直列方向上都可以激发直至第五模式的更高振动模式。奇数和偶数模式都在错流和串联方向上被激发。随着汽缸之间的分离距离增加，振荡的幅度会在更大范围的降低的速度范围内增加。研究了运动的横向轨迹，并识别了沿圆柱体长度方向被流动激励或阻尼的区域，即，具有正，负流动力系数与速度同相的区域。