ABSTRACT

Concrete semi-submersible floating wind turbines (FWTs) have generated increasing interest in the offshore wind energy industry due to their superiority over steel structures in aspects of construction and maintenance. However, the influence of construction materials on the dynamics of FWTs was scarcely studied before. The dynamics of two FWTs, mounted on a concrete and a steel Y-shaped semi-submersible platform respectively, are investigated by means of 1:60 scale combined wind and wave model tests and coupled multi-body simulations. The results indicate that the steel structure with a lower centre of gravity exhibits advantages in platform pitch motion alleviation. The steel structure is also subjected to lower pitch-induced tower base loads and nacelle acceleration than its concrete counterpart. However, an opposite trend is found in the wave-frequency responses, leading to an insignificant difference of tower base loads and nacelle acceleration between the two structures.

ABBREVIATIONS: FWTs: Floating wind turbines; CoG: Centre of gravity; CoB: Centre of buoyancy; LCP3: Lightweight prestressed concrete platform; HSP3: High-strength steel platform; WTWF: Wind tunnel and wave flume joint laboratory; ROC: Rated operational condition; JONSWAP; Joint North Sea Wave Observation Projection; RAO: Response amplitude operator; BEM: Blade element momentum theory; DOF: Degree of freedom; GDW: Generalised dynamic wake theory; PSD: Power spectral density; QTF: Quadratic transfer function

摘要

混凝土半潜式浮式风力涡轮机（FWT）因其在建造和维护方面优于钢结构而在海上风能行业引起了越来越多的关注。然而，以前很少研究建筑材料对 FWT 动力学的影响。通过1:60比例的风浪组合模型试验和耦合多体仿真研究了分别安装在混凝土和钢Y形半潜平台上的两个FWT的动力学。结果表明，重心较低的钢结构在减轻平台俯仰运动方面具有优势。与混凝土对应物相比，钢结构还承受较低的俯仰引起的塔基载荷和机舱加速度。然而，

缩写： FWTs：浮动风力涡轮机；CoG：重心；CoB：浮力中心；LCP3：轻质预应力混凝土平台；HSP3：高强度钢平台；WTWF：风洞与波槽联合实验室；ROC：额定工作条件；琼斯瓦普；联合北海波浪观测投影；RAO：响应幅度算子；BEM：叶片元动量理论；DOF：自由度；GDW：广义动态尾流理论；PSD：功率谱密度；QTF：二次传递函数