Dynamics of Offshore Wind Turbine Platforms

风能现在被认为是最经济可行的替代能源形式——在某些情况下，它的发电成本比传统能源低。风力涡轮机产生的能源也有一定的缺点，包括间歇性和当地利益集团的反对。将风力涡轮机放置在海上可以克服其中一些障碍：海上风力更强，更稳定，涡轮机基本上在视线之外，因此吸引的反对意见更少。迄今为止，所有的海上风力涡轮机装置都是“固定底部”的：支撑平台被牢固地固定在海底，深度为20-30米。然而，人们越来越有兴趣将涡轮机放置在离岸更远的漂浮平台上，在数百米深处。海上浮动式风力涡轮机由一个高桅杆上的水平轴涡轮机组成。桅杆安装在一个浮力平台上，浮力平台有很多种类型，这个平台通过一排电缆固定在海底。由于涡轮叶片、臂架和系索的灵活性，这些系统的动力学非常复杂。本文提出的研究重点是这些多系留海上平台的动力学和设计。目标是评估建议的设计，并最终提出新的设计，基于这些系统的分析。我们过去在类似的多系绳浮力系统中的经验，使我们对这些复杂系统的行为有了许多不同寻常的认识。

Wind energy is now acknowledged to be the most economically viable form of alternative energy---in some cases producing power at lower cost than conventional sources. Energy produced by wind turbines also has certain drawbacks, including intermittency and opposition by local interest groups. Placing wind turbines offshore can overcome some of these obstacles: offshore wind is stronger and more consistent, and the turbines are largely out of sight, thus attracting less opposition. To date, all offshore wind turbine installations have been 'fixed-bottom': the supporting platform is rigidly anchored to the seabed, in depths of 20-30 m. However, there is increasing interest in placing turbines farther offshore on floating platforms, in depths of hundreds of meters. An offshore floating wind turbine is composed of a horizontal axis turbine atop a tall mast. The mast is mounted on a buoyant platform, of which there are many types, and that platform is anchored to the seabed by an array of cables. The dynamics of these systems is complex due to the flexibility of the turbine blades, the boom and the tethers. The research proposed here focuses on the dynamics and design of these multi-tethered offshore platforms. The goal is to evaluate proposed designs, and eventually to propose new designs, based on analysis of these systems. Our past experience in analogous multi-tethered buoyant systems provides us many uncommon insights into the behavior of these complex systems.