新型FDPSO涡激运动试验研究

Experimental study on vortex-induced motions of a new type FDPSO

以一座工作水深为1500m的新型深吃水变截面多立柱式FDPSO为研究对象,对其在300m等效截断水深锚泊系统系泊时的涡激运动特性开展了模型试验研究.模型试验在上海交通大学海洋工程国家重点实验中进行,缩尺比取为1:80.本文重点对不同工况下平台的横向涡激运动、响应谱和运动轨迹进行了系统性研究.研究结果表明:平台的横向运动频率未出现典型'锁定'现象,而是一直保持在接近固有横荡频率的范围内;同一流向下,平台纵向运动的平衡位置与最大振幅均随着折合速度的增加而增加.与其他经典平台相比,本文新型FDPSO最大横荡振幅值随折合速度的变化呈现不同的趋势.随着折合速度的增加,横荡运动的最大振幅与标称振幅之间的差值增大.

The design of 300m water depth equivalent truncated mooring system was adopted for model tests of the deep draft multi-column FDPSO operating in 1500m water depth. Model tests were carried out to check the influences of different current incidence angles and reduced velocities. The results comprise surge, sway and yaw motions, as well as motion trajectories. Based on that, spectral analysis of the three motions and the tension of mooring system are discussed. Comparison of maximum sway amplitudes for different types of offshore platform is also studied. The main results show that the peak frequencies of sway motion under different current incidence angles and reduced velocities have been kept around the natural frequency. In the same current direction angle, both the equilibrium position and the maximum amplitude of sway motion increase with the increase of the reduced velocity. Compared with other classical platforms, the variation trend of maximum sway amplitudes with the reduced velocity is different. With the increase of reduced velocity, the difference between the maximum amplitude and the nominal amplitude of sway motion increases.