This study introduces a numerical model designed to simulate interactions occurring between a wind turbine's tower and the surrounding soil, as well as between the nacelle, blades, and the surrounding environment. This simulation accounts for both fore–aft and side-to-side movements. To describe these interactions, the model leverages the Euler–Lagrange equations. It calculates wave loads utilizing the Morison equation, with wave data generated based on the JONSWAP spectrum. Furthermore, aerodynamic loads are determined using the blade element moment theory, and the wind spectrum is generated using the Von Karman turbulence model. The tower is represented as a variable cross-sectional beam, employing a two-noded Euler beam element with two degrees of freedom: transverse displacement and rotation, and utilizing Hermite polynomial shape functions. In a comparative analysis against experimental data, this modified model demonstrates significant enhancements in accurately reproducing the dynamic behavior of wind turbines with variable cross-sectional towers, outperforming models that approximate the tower with a constant cross section. Our findings reveal that the modified model achieves a remarkable improvement of 15% in replicating the tower's dynamic response when compared to the constant cross-sectional models. As a case study, a 5 MW monopile wind turbine with a flexible foundation, specifically the one provided by the National Renewable Energy Laboratory (NREL), is employed to simulate its dynamic response. This research presents a robust numerical model for simulating wind turbine behavior in various environmental conditions. The incorporation of variable cross-sectional tower representation significantly improves the model's accuracy, making it a valuable tool for assessing wind turbine dynamics. The study's findings highlight the importance of considering tower flexibility in wind turbine simulations to enhance their real-world applicability.

中文翻译：

---

风浪载荷作用下海上风力发电机双向叶片-塔架-土壤-结构动力相互作用的变截面效应

本研究介绍了一个数值模型，旨在模拟风力涡轮机塔架与周围土壤之间以及机舱、叶片与周围环境之间发生的相互作用。该模拟考虑了前后和左右运动。为了描述这些相互作用，该模型利用欧拉-拉格朗日方程。它利用 Morison 方程计算波浪载荷，并根据 JONSWAP 频谱生成波浪数据。此外，使用叶片单元力矩理论确定空气动力载荷，并使用冯卡门湍流模型生成风谱。该塔被表示为变截面梁，采用具有两个自由度的二节点欧拉梁单元：横向位移和旋转，并利用埃尔米特多项式形状函数。在与实验数据的比较分析中，该修改后的模型显示出在精确再现具有可变横截面塔架的风力涡轮机的动态行为方面的显着增强，优于近似具有恒定横截面的塔架的模型。我们的研究结果表明，与恒定横截面模型相比，修改后的模型在复制塔的动态响应方面取得了 15% 的显着改进。作为案例研究，采用具有柔性基础的 5 MW 单桩风力涡轮机（特别是由国家可再生能源实验室 (NREL) 提供的）来模拟其动态响应。这项研究提出了一个强大的数值模型，用于模拟风力涡轮机在各种环境条件下的行为。可变横截面塔架表示的结合显着提高了模型的准确性，使其成为评估风力涡轮机动力学的宝贵工具。该研究的结果强调了在风力涡轮机模拟中考虑塔架灵活性以增强其现实世界适用性的重要性。