Wave-Structure Interaction of Floating Wind Turbines - A Combined Numerical and Experimental Investigation

0967023 Zhu浮动式风力涡轮机是一种新型的可再生能源设备，设计用于在沃茨（60 m）中运行，大多数海上风能资源都在深水中发现。这些浮动式涡轮机在结构上不同于其他现有的海上系统，其在海上条件下的结构稳定性尚未得到广泛测试。 智力优势这项跨学科研究工作将利用地震工程实验设施和最先进的计算方法来研究海浪中浮动风力涡轮机的动态结构响应。 两个模型，频域模型和非线性时域模型，将被开发来研究流体-结构相互作用问题。 对于波体相互作用的模拟，第一个模型使用线性边界元模型，而第二个模型应用完全非线性混合欧拉-拉格朗日方法。 这两个模型包括一个全面的，完全非线性动力学模型的系泊系统和有限元模型的结构响应。双模型方法能够研究系统的长期响应（例如疲劳研究）和由于大浪（例如异常波）引起的瞬态响应。 该研究计划将集中在三个领域：波浪场中的长期结构响应，波浪结构共振和对大浪的响应。对于模型验证研究，将在65 kW系统上进行全尺寸振动台实验，并将记录的结构响应与模型预测进行比较。 该模型将被用来预测一个放大5兆瓦系统的性能。 这项研究具有潜在的变革性，因为它将提供新的工具来评估目前浮动风力涡轮机设计的可行性。 这项研究的一个独特之处在于它使用地震工程工具，特别是加州大学圣地亚哥分校的大型高性能户外振动台来研究海上风能结构。除了直接参与研究工作的本科生和研究生的培训外，基于他们研究的学习材料将被纳入现有的本科生和研究生结构和流体力学课程。其他活动包括在圣地亚哥的加州大学使用大型高性能户外摇床作为示范，以接触到来自代表性不足群体的K-12学生，讨论与可再生能源有关的主题。 该设施的网站将更新，包括浮动风力涡轮机。

0967023ZhuFloating wind turbines are novel renewable energy devices designed to operate in deep waters (60 m), where most of the offshore wind energy resource is found. These floating turbines are structurally different from other existing offshore systems, and their structural stability in offshore conditions has not been extensively tested. Intellectual Merit This interdisciplinary research effort will make use of an experimental facility for earthquake engineering and state-of-the-art computational methods to study the dynamic structural responses of floating wind turbines in ocean waves. Two models, a frequency-domain model and a nonlinear time-domain model, will be developed to study the fluid-structure interaction problem. For simulations of wave-body interaction, the first model uses a linear boundary element model, while the second model applies a fully-nonlinear mixed-Eularian-Lagragian method. Both models include a comprehensive, fully-nonlinear dynamic model of the mooring system and a FEM model of the structural responses. The two-model approach enables the study of both long-term responses of the system (e.g. for fatigue studies) and transient response due to large waves (e.g. rogue waves). The research plan will focus on three areas: long-term structural response in wave fields, wave-structure resonances, and responses to large waves. For the model verification studies, full-scale shake table experiments will be carried out on a 65 kW system, and the recorded structural responses will be compared with model predictions. The models will then be used to predict the performance of a scaled-up 5 MW system. This research is potentially transformative because it will provide new tools to evaluate the feasibility of current designs for floating wind turbines. This research could also be used to guide the development of future deep-water offshore wind farms.Broader Impacts A unique aspect of this work is that it uses earthquake engineering tools, specifically the Large High-Performance Outdoor Shake Table at University of California - San Diego, to study offshore wind energy structures.In addition to training of undergraduate and graduate students directly involved in the research effort, learning materials based on their research will be incorporated into existing undergraduate and graduate structural and fluids mechanics courses. Other activities include using the Large High-Performance Outdoor Shake Table at University of California at San Diego as a demonstration to reach out to K-12 students from under-represented groups on topics related to renewable energy. Websites for this facility will be updated to include the floating wind turbine.