The present paper investigates the significance of gyroscopic effects on responses of floating offshore wind turbines (FOWTs). A 17-degree-of-freedom (DOF) FOWT model is rigorously developed using the Euler-Lagrange approach. Based on rational approximation of the radiation loads, an extended state-space formulation is then established for the coupled mechanical-hydrodynamic-controller system, enabling very efficient time-domain simulations. Different strategies for deriving linear system equations of motion (EOMs) within the Euler-Lagrange framework are evaluated, with the focus of highlighting the correct procedure for capturing the full gyroscopic couplings in linear EOMs. Monte Carlo simulations are performed on three scenarios, i.e. no aerodynamics, idling FOWTs and operational FOWTs. It is observed that gyroscopic couplings significantly influence the tower torsion (and possibly foundation yaw depending on the foundation type) of FOWTs without aerodynamic loads, and the spar-type FOWT is most sensitive to gyroscopic effects among the three concepts considered (although the TLP can be similarly sensitive). The aerodynamic loads are the dominating loads for both idling and operational FOWTs, and the gyroscopic effect becomes less significant although it still plays a more important role in operational FOWTs than idling FOWTs. Excluding the gyroscopic effect leads to non-negligible overestimation of the tower torsion of the operational FOWT. This study unfolds the correct derivation procedure, the mathematical formulas, the physical mechanism and the influence/significance regarding the gyroscopic effects in FOWTs, which also acts as a useful guideline for developing in-house reduced-order FOWT models.

本文研究了陀螺效应对浮式海上风力涡轮机（FOWT）响应的重要性。使用Euler-Lagrange方法严格开发了17自由度（DOF）FOWT模型。基于辐射负荷的合理近似，然后为耦合的机械-流体动力控制器系统建立了扩展的状态空间公式，从而可以进行非常有效的时域仿真。对在欧拉-拉格朗日框架内推导线性系统运动方程（EOM）的不同策略进行了评估，重点是重点介绍了捕获线性EOM中完整陀螺仪耦合的正确过程。蒙特卡罗模拟是在三种情况下执行的，即无空气动力学，空转FOWT和可操作FOWT。可以看出，陀螺耦合对无空气动力载荷的FOWT的塔架扭转（可能取决于基础类型的基础偏航）有显着影响，而翼梁式FOWT对所考虑的三个概念中的陀螺效应最敏感（尽管TLP可以同样敏感）。空气动力学负载是空载和运行FOWT的主要负载，陀螺效应变得不那么重要，尽管它在空载FOWT中比空载FOWT仍然起着更重要的作用。排除陀螺效应会导致对运行中的FOWT塔架扭转的不可估量的高估。这项研究展开了正确的推导程序，数学公式，物理机制以及有关FOWT陀螺效应的影响/意义，