Numerical models have been used extensively in the design process of the TetraSpar floating offshore wind turbine (FOWT) foundation to optimize and investigate the influence from a number of structural and environmental conditions. In traditional offshore design, either the Morison approach or a linear boundary element method (BEM) is applied to investigate the hydrodynamic loads on a structure. The present study investigated and compared these two methods and evaluated their applicability on the TetraSpar FOWT concept. Furthermore, a hybrid model containing load contributions from both approaches was evaluated. This study focuses on motion response. In the evaluation, hydrodynamic data from BEM codes are applied, while the commercial software package OrcaFlex is utilized for time series simulations of the coupled structure. The investigation highlights the difference between the modelling approaches and the importance of particularly drag and inertia contributions. By optimizing the input coefficients, reasonable agreement between the models can be achieved.

中文翻译：

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浮动海上风力涡轮机基础的流行水动力建模方法的比较研究：TetraSpar 案例研究

数值模型已广泛用于 TetraSpar 浮动式海上风力涡轮机 (FOWT) 基础的设计过程中，以优化和研究多种结构和环境条件的影响。在传统的海上设计中，Morison 方法或线性边界元方法 (BEM) 用于研究结构上的水动力载荷。本研究调查并比较了这两种方法，并评估了它们在 TetraSpar FOWT 概念上的适用性。此外，还评估了包含来自两种方法的负载贡献的混合模型。本研究侧重于运动反应。在评估中，应用了 BEM 代码的流体动力学数据，而商业软件包 OrcaFlex 则用于耦合结构的时间序列模拟。调查强调了建模方法之间的差异以及特别是阻力和惯性贡献的重要性。通过优化输入系数，可以实现模型之间的合理一致性。