浮式风机浮台中的非线性能量阱减振性能

Vibration reduction performance of a nonlinear energy sink installed in the platform of floating wind turbine

摘要:

海上风电机组的大型化使得浮式风机在恶劣海况下服役时面临的振动问题日益严重,其复杂的流固耦合机制以及多模式振动特性,让仅能针对单一振动频率调谐的传统被动减振装置存在局限。为此,提出利用具有宽频减振特性的非线性能量阱(NES)对张力腿浮式风机(TLP-FWT)进行振动控制,以探索适用于多模式振动控制的新型减振策略。首先,基于达朗贝尔原理建立TLP-FWT-NES动力学模型,并采用Leven-Marquardt算法对模型参数进行修正。随后,结合网格搜索与贝叶斯优化方法对NES参数进行优化,并与调谐质量阻尼器(TMD)的性能进行对比分析。最后,利用OpenFAST在多种海况下进行全耦合数值模拟,对NES的减振性能进行综合评估。研究结果表明:NES相较于TMD对自身刚度参数变化更具鲁棒性；NES通过共振俘获级联机制能够实现多阶振动能量的捕获与转移,且高阶振动作为控制目标时其多阶振动控制性能更为显著；全耦合数值模拟表明在极端工况下二者均能有效抑制结构振动响应,然而在单一振动频率控制场景下,NES的减振性能并不优于TMD。该研究成果为探索浮式风机的多模式振动控制提供了新的思路,对提升大型浮式风电机组在复杂海况下的运行安全性与结构可靠性具有一定参考价值。

Abstract:

The trend towards larger offshore wind turbines has led to increasingly severe vibration issues for floating wind turbines operating in harsh sea conditions. The complex fluid-structure interaction and multi-mode vibration characteristics of such structures highlight the limitations of conventional passive vibration absorbers, which can only be tuned to a single frequency. To address this issue, this paper proposes the application of a nonlinear energy sink (NES) with broadband vibration reduction capability to the tension leg platform floating wind turbine (TLP-FWT), aiming to develop a novel vibration reduction strategy suitable for multi-mode responses. A dynamic model of the TLP-FWT-NES was first established based on D′Alembert′s principle, and its parameters were corrected using the Leven-Marquardt algorithm. Subsequently, the NES parameters were optimized through a combination of grid search and Bayesian optimization, and its performance was compared with that of a tuned mass damper (TMD). Finally, fully coupled numerical simulations under various sea states were carried out using the OpenFAST to comprehensively evaluate the vibration reduction performance of the NES. The results demonstrate that the NES exhibits greater robustness to stiffness variation than the TMD, through the mechanism of resonance capture cascade and targeted energy transfer, it can effectively suppress multiple vibration modes when high-order modes are selected as the optimization target. However, in single-mode control scenarios, the NES does not outperform the TMD, while under extreme sea states, both devices are capable of reducing structural vibration, with the TMD showing superior overall effectiveness. This study provides new insights into multi-mode vibration control of floating wind turbines and offers a useful reference for enhancing the operational safety and structural reliability of large-scale floating wind turbines under complex marine conditions.