段塞流诱导柔性立管振动响应实验分析

在气液两相循环实验系统中开展了水动力段塞流诱导的悬链线型柔性立管振动响应测试，利用高速摄像非介入测试方法同步捕捉了柔性立管的振动位移与管内的段塞流动细节，预测了气体表观流速对水动力段塞流诱导柔性立管振动响应的影响规律，分析了振幅响应、模态权重、频谱变化以及管内流动特性。结果表明，随着气体表观流速的增大，振动幅度逐渐增大，模态交互作用逐渐增强，尽管高阶振动模态权重不断增大，但一阶模态在立管振动响应中始终占据主导；对于较小的气体表观流速，振动响应主要归因于短段塞的不稳定流动，对于较大的气体表观流速，振动响应主要取决于长段塞的流动频率；气体表观流速增大使管内流动速度、段塞长度逐渐增大，而持液率逐渐减小。

An Experimental Investigation on the Slug Flow-induced Vibration of Flexible Riser

Experiments on hydrodynamic slug flow-induced vibration of flexible riser at different gas superficial velocities were carried out in the air-water test loop using the non-intrusive measurement with high-speed cameras. The vibration displacements were synchronously captured with the internal flow regimes. The dynamic characteristics of flexible riser are analyzed in terms of the amplitude response, modal weight, frequency variation as well as the slug flow characteristics. The results indicate that the amplitude is amplified, and the modal interaction is enhanced with increasing the gas superficial velocity. The fundamental mode dominates the vibration response despite the growth in the modal weight of higher ones. The flow instability of short slugs mainly contributes to the response when the gas superficial velocity is relatively small. In contrast, the response is closely related to the occurrence frequency of long slugs at larger gas superficial velocities. Additionally, both the slug length and migration velocity are enlarged with increasing the gas superficial velocity, while the liquid holdup is reduced.