剪切来流下柔性立管涡激振动抑制装置试验研究

文章针对柔性立管螺旋列板抑制装置在剪切流场中的涡激振动响应特性进行了试验研究，试验过程中通过旋转臂架从而形成相对剪切来流。通过测试得到的应变数据，基于模态叠加法，可得到立管的位移响应等参数。试验中针对螺旋列板的螺距和鳍高的变化进行了分析，系统地研究了不同螺旋列板状态下立管的主导频率、主导模态、无量纲振幅比以及疲劳损伤等参数。研究结果表明：螺旋列板可以很好地抑制立管的涡激振动响应；与螺距相比，鳍高对立管涡激振动响应会带来更大的影响；剪切流场中立管螺距恒定为5.0D（D为立管外径）时，鳍高为0.15D时的立管具有最好的抑制效果。

Experimental investigation on the suppression device of VIV of a flexible riser in sheared currents

Laboratory test was conducted on the flexible riser with helical strakes in order to understand its response characteristics in sheared currents. The relative sheared currents were simulated by rotating the cantilever during the experiment. Based on the modal analysis method, the displacement responses can be obtained by the measured strain. The strakes with different heights and pitches were analyzed, and the re-sponse parameters such as dominant frequency, dominant mode, non-dimensional displacement and fatigue damage were studied. The analysis results indicate that helical strakes can suppress vortex induced vibra-tion (VIV) response effectively. Compared with strake pitch, strake height has greater influence on the VIV response. When the given pitch is 5.0D (D is the external diameter of the riser) in the sheared current, the 0.15D height always has the best suppression efficiency.