As the size of offshore wind turbines increases, a realistic representation of the spatiotemporal distribution of the incident wind field becomes crucial for modeling the dynamic response of the turbine. The International Electrotechnical Commission (IEC) standard for wind turbine design recommends two turbulence models for simulations of the incident wind field, the Mann spectral tensor model, and the Kaimal spectral and exponential coherence model. In particular, for floating wind turbines, these standard models are challenged by more sophisticated ones. The characteristics of the wind field depend on the stability conditions of the atmosphere, which neither of the standard turbulence models account for. The spatial and temporal distribution of the turbulence, represented by coherence, is not modeled consistently by the two standard models. In this study, the Mann spectral tensor model and the Kaimal spectral and exponential coherence model are compared with wind fields constructed from offshore measurements and obtained from large‐eddy simulations. Cross sections and durations relevant for offshore wind turbine design are considered. Coherent structures from the different simulators are studied across various stability conditions and wind speeds through coherence and proper orthogonal decomposition mode plots. As expected, the standard models represent neutral stratification better than they do stable and unstable. Depending upon the method used for generating the wind field, significant differences in the spatial and temporal distribution of coherence are found. Consequently, the computed structural design loads on a wind turbine are expected to vary significantly depending upon the employed turbulence model. The knowledge gained in this study will be used in future studies to quantify the effect of various turbulence models on the dynamic response of large offshore wind turbines.

中文翻译：

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评估不同风场以研究海上风力涡轮机的动力响应

随着海上风力涡轮机尺寸的增加，入射风场的时空分布的真实表示对于建模涡轮机的动态响应变得至关重要。国际电工委员会（IEC）的风力涡轮机设计标准推荐了两种湍流模型（用于模拟入射风场），曼光谱张量模型以及Kaimal光谱和指数相干模型。特别是对于浮动式风力涡轮机，这些标准模型面临着更为复杂的模型挑战。风场的特性取决于大气的稳定性条件，这两种标准湍流模型都没有考虑。用连贯性表示的湍流的时空分布不是由两个标准模型一致地建模的。在这项研究中，Mann光谱张量模型，Kaimal光谱和指数相干模型与通过海上测量构建并通过大涡模拟获得的风场进行了比较。考虑与海上风机设计有关的横截面和持续时间。通过相干性和适当的正交分解模式图，研究了来自不同模拟器的相干结构，其跨各种稳定性条件和风速进行了研究。不出所料，标准模型比稳定模型和不稳定模型更好地表示中性分层。取决于用于产生风场的方法，发现相干的空间和时间分布上存在显着差异。所以，根据所采用的湍流模型，预计风力涡轮机上计算出的结构设计载荷将发生显着变化。在这项研究中获得的知识将用于未来的研究中，以量化各种湍流模型对大型海上风力涡轮机动力响应的影响。