An experimental investigation of vortex-induced vibration of a curved flexible pipe in shear flows
An experimental investigation of vortex-induced vibration of a curved flexible pipe in shear flows
复制标题
剪切流中弯曲软管涡激振动的实验研究
DOI：
10.1016/j.oceaneng.2016.05.025
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发表时间：
2016
影响因子：
5
通讯作者：
Yao Jie
中科院分区：
文献类型：
--
作者：
Zhu Hongjun;Lin Pengzhi;Yao Jie
对弯曲柔性管道在剪切流场中的涡激振动进行了实验研究。弯曲管完全浸入水中，纵横比为108，质量阻尼比为0.11。利用高速成像技术，对管道在15种不同流速剪切流作用下的顺向和横向振动位移进行了记录。振幅和频率与雷诺数范围从165到1129的折合速度。结果表明，管道不同位置处存在不同的振动频率，呈现多模态响应，激励模态随来流速度的变化而变化。顺时针方向上的最高模式是第三模式，而在横流方向上它是第二模式。管道的中间部分呈现八字形轨迹，而管道两端的轨迹演化为半月形格式。流场显示结果表明，在二阶响应的两个峰值对应的位置出现2P或P+S尾迹型，而2S尾迹型主要出现在波谷对应的位置。尾流在一阶响应峰值处主要表现为P+S模态，在其它位置主要表现为2S模态。
Vortex-induced vibration (VIV) of a curved flexible pipe in shear flows was studied experimentally in the concave configuration. The curved pipe was fully immersed into the water with the aspect ratio of 108 and mass-damping ratio of 0.11. The high speed imaging technology was employed to record the pipe's vibration displacements in both in-line and cross-flow directions subject to the shear flows with 15 different velocities. Both amplitude and frequency are presented versus the reduced velocity for a Reynolds number ranging from 165 and 1129. The results reveal that different vibration frequencies exist at different positions of the pipe with the presentation of multi-mode-response, and the excited modes vary with the incoming speed. The highest mode in the in-line direction is the third mode, while it is the second mode in the cross-flow direction. Eight-shape trajectories are presented in the middle part of the pipe, while the trajectories evolve to half-moon format at the two ends of pipe. Flow visualizations show that 2P or P+S wake pattern presents at the locations corresponding to the two peaks of the second-order response, while 2S pattern mainly appears at the position corresponding to the trough. The wake mainly presents a P+S mode at the location corresponding to the peak of the first-order response, while 2S mode is the main pattern in other locations.