Recently, a growing interest has been seen in vortex induced motions of offshore units. These induced motions are significantly relevant for the design of mooring systems and risers of offshore platforms. This work analyzes the vortex induced motions (VIM) of a Tension Leg Platform (TLP) when submitted to currents. The model tests were carried out in the fKN@LOC/COPPE-UFRJ laboratory facilities. Furthermore, a novel arrangement to represent the TLP tendons in shallow current channels is presented and discussed. This experimental set-up is innovative since, to avoid the set down, a tower has been implemented. TLP vertical motions are restrained and necessary stiffness for horizontal modes is provided by springs. The ultra-reduced model with four square columns and four pontoons in closed configuration was built using a scale of 1:200. The range of current velocities was from 0.33 to 2.59 m/s. and five angles of attack were considered: 0, 11.25, 22.50, 33.75, 45 degrees. The reduced velocity reached a very high value of 32 for 45 degrees of heading. Results have shown that the induced motions are dependent on the angle of attack and the current speed. For zero degrees of heading a typical bell curve of VIM was observed. On the other hand, for 45 degrees, motions increase steadily with current speed.
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机译：最近，在涡旋诱导的海上单位运动中已经看到了日益增长的兴趣。这些诱导的动作对于海上平台的系泊系统和立管的设计具有显着相关。当提交给电流时，这项工作分析了张力腿平台（TLP）的涡旋诱导的运动（Vim）。模型测试是在FKN @ LOC / COPPE-UFRJ实验室设施中进行的。此外，提出并讨论了一种以表示浅电流通道中的TLP诱拐的新布置。这种实验设置是创新的，因为避免设置，塔已经实施。受到TLP的垂直运动，并通过弹簧提供水平模式的必要刚度。使用1：200的等级构建了具有四个方形柱和四个浮翅的超减少模型。电流速度范围为0.33至2.59 m / s。和五个角度被认为是：0,11.25,22.50,33.75,45度。降低的速度达到45度的值为45度。结果表明，诱导的运动依赖于攻击和电流速度。对于零度的前进程度，观察到Vim的典型钟曲线。另一方面，对于45度，动作随着电流速度稳定地增加。
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