内外流耦合作用下柔性立管振动响应特性研究  

Experimental investigation on the flow-induced vibration of a riser subjected to the combination of internal liquid flow and external sheared flow

作　　者：高岳 朱红钧 胡洁 许兵 GAO Yue;ZHU Hongjun;HU Jie;XU Bing(Petroleum Engineering School,Southwest Petroleum University,Chengdu 610500,China)

机构地区：[1]西南石油大学石油与天然气工程学院,成都610500

出　　处：《实验流体力学》2024年第5期44-53,共10页Journal of Experiments in Fluid Mechanics

基　　金：国家自然科学基金青年科学基金项目(52301338);国家自然科学基金面上项目(51979238);四川省青年基金项目(2024NSFSC0968)。

摘　　要：柔性立管广泛应用于海洋油气等矿产资源的输送,在内部流体与外部海流的夹击下极易产生复杂的振动响应,一旦发生疲劳失效,就会造成严重的环境污染。在循环水槽中开展了单相内流与非线性剪切外流耦合作用下悬链线型柔性立管的振动响应测试,采用高速摄像非介入测试方法捕捉了悬链线型柔性立管的振动位移。通过改变非线性剪切外流的约化速度(U_(r)^(m)=3.55~44.69)和内流流速(u_(i)=0.674~1.651 m/s),分析了内流流速对柔性立管振动响应的影响规律,剖析了不同流动工况下平面外振幅、振频的时空响应特性及振动模态的演变。实验结果表明:与纯外流激发的涡激振动相比,内流的存在使柔性立管的振幅增大,且振动模态转换发生在更低的约化速度,随着内流流速的增大,相邻模态间发生模态转换的临界约化速度越来越低;在本实验测试工况下,当柔性立管在纯外流作用下发生锁频振动时,振动模态没有发生改变,而在外流涡激振动处于模态过渡区时,内流的输送易使高阶模态在更低的约化速度时出现。Flexible risers which are commonly applied to transport submarine resources have been widely utilized in offshore engineering.The intricate Flow-Induced Vibration(FIV)of flexible risers is easily encountered with the presence of both internal and external flows.Once the riser fatigue failure occurs,it causes serious environmental pollution.In this work,a series of tests were conducted in a recirculating water flume to investigate the dynamic behavior of a flexible catenary riser under the combination of the internal liquid water flow and the external shear current.A non-intrusive high-speed imaging technique was employed to record the vibration displacement varying along the riser span.The reduced velocity and the internal flow velocity ranged from 3.55 to 44.69 and from 0.674 m/s to 1.651 m/s,respectively.The influence of the internal flow velocity on the dynamic response was examined.The experimental results including the spatial-temporal response amplitude and frequency as well as the mode evolution of out-of-plane were analyzed.The results show that the response is enhanced with increasing internal flow velocity except for the mode transition cases.In addition,the existence of the internal flow leads to the earlier occurrence of the mode transition.When the lock-in occurs in the vortex-induced vibration of the flexible riser,the amplitude of the flexible riser is magnified with increasing internal velocity,while the new mode response is not triggered.There is a new mode response occurring in the mode transition cases.

关 键 词：流致振动 柔性立管 内流 剪切流 非介入测试 

分 类 号：TE58[石油与天然气工程—油气田开发工程] P751[交通运输工程—港口、海岸及近海工程]