This paper presents analytical and numerical analyses on self-induced vibration of Ocean Thermal Energy Conversion (OTEC) Cold Water Pipe (CWP) for a 100 MW-net OTEC power plant. The CWP is described as a vertically-hanged, top-tensioned riser subjected to internal flow effect (IFE) and ambient fluid effects (added mass and drag force). In the analytical analysis, two definitions of the drag force equation in the frequency-domain term and time-domain term are considered yielding a linear differential equation and a non-linear differential equation. The stability is assessed by discretizing the equations using Frobenius method and Galerkin Method and then plotting its eigenfrequencies or its eigenvalues in an Argand diagram. Separately, a fully-coupled fluid-structure interaction is carried out in a numerical simulation for particular cases. The scantlings of the riser are chosen from the available size of Fiber Reinforced Plastic (FRP) pipe in a manufacturer and varied accordingly for future production capacity development. The riser is pinned at the top and mounted at the bottom. Results indicate that the predicted critical velocity in the time domain is averagely 20% higher compared to the frequency domain. The effect of the clump weight on the critical velocity is more significant for light material compared with relatively high-density material.

本文介绍了一个100 MW净OTEC电厂的海洋热能转换（OTEC）冷水管（CWP）自感应振动的分析和数值分析。CWP被描述为承受内部流动效应（IFE）和环境流体效应（增加的质量和阻力）的垂直悬挂的，顶部张紧的立管。在分析分析中，考虑了在频域项和时域项中的阻力方程的两个定义，从而得出线性微分方程和非线性微分方程。通过使用Frobenius方法和Galerkin方法离散化方程，然后在Argand图中绘制其特征频率或特征值，可以评估稳定性。另外，对于特殊情况，在数值模拟中进行了完全耦合的流固耦合。立管的尺寸是从制造商的可用纤维增强塑料（FRP）管尺寸中选择的，并根据将来的生产能力发展而相应地变化。提升板固定在顶部，底部安装。结果表明，与频域相比，时域中的预测临界速度平均要高20％。与相对高密度的材料相比，轻质材料的团块重量对临界速度的影响更为显着。结果表明，与频域相比，时域中的预测临界速度平均要高20％。与相对高密度的材料相比，轻质材料的团块重量对临界速度的影响更为显着。结果表明，与频域相比，时域中的预测临界速度平均要高20％。与相对高密度的材料相比，轻质材料的团块重量对临界速度的影响更为显着。