摘要
该文基于Van Der Pol尾流振子模型,研究了两端铰接的柔性立管在不同约化速度下横向和流向的振动响应特性。采用二阶中心差分法对时域和空间域的耦合方程组进行了迭代求解,并与现有文献的实验数据和模型预测结果进行了对比。结果表明:随约化速度的增大,高阶模态在两个方向逐渐被激发出来,主导模态转移时,出现均方根振幅跃升的现象。两个方向主导振动模态比在一定的约化速度范围内保持不变,将其定义为模态组。在同一个模态组中,横向和流向的均方根振幅均随着约化速度单调增加,但在主导模态转移时,两个方向的频率比均发生跳跃。在模态过渡组次,立管的振动响应呈多模态共同参与,且在振动过程中,振动模态具有在空间上竞争和时间上切换的特征,主导频率能量较为集中,在模态切换的过程中出现的频次也更大。
With the aid of Van Der Pol wake oscillator model,in the present work the vibration response characteristics of a pinned-pinned flexible riser are investigated at different reduced velocities.The coupling equations of time and space domain are solved using a standard second-order central finite difference method.The numerical method is validated with reported experimental data and model prediction results.Present calculation results show that the higher-order modes are excited in both two directions with increasing the reduced velocity,and the root-mean-squared amplitude experiences a jump during the dominant mode transition.The ratio of the dominant mode numbers in the two directions remains unchanged in a certain reduced velocity range,defined as a modal group.In the same modal group,the root-mean-squared amplitudes in both in-line and cross-flow directions increase monotonically with the reduced velocity,while the freq uency ratio jumps during the dominant mode transition.In the mode transition cases,the response presents mu lti-mode features,exhibiting the spatial mode competition and temporal mode switching.The vibration energy concentrates at the dominant frequ ency,and the dominant mode occurs more frequently in the switching.
作者
朱红钧
丁志奇
Hong-jun Zhu;Zhi-qi Ding(Petroleum Engineering School,Southwest Petroleum University,Chengdu 610500,China)
出处
《水动力学研究与进展（A辑）》
CSCD
北大核心
2022年第3期335-344,共10页
Chinese Journal of Hydrodynamics
基金
国家自然科学基金面上项目(51979238)
大连理工大学海岸和近海工程国家重点实验室开放基金(LP1930)。
关键词
尾流振子模型
柔性立管
模态转移
模态组
模态切换
Wake oscillator model
Flexible riser
Mode transition
Modal group
Mode switching
