Junlei Wang, Haoran Li, Jisheng Zhang, Dawei Guan, Hao Chen, Tao Lu
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引用次数: 0
Abstract
The pitch motion of floating offshore wind turbines (FOWTs) significantly reduces energy conversion efficiency and accelerates fatigue degradation of blades and tower. This study proposes a passive control strategy using gyro stabilizers to mitigate platform pitch instability in a semi-submersible FOWT prototype based on the Tri-floater design. Scaled hydrodynamic model tests were conducted to evaluate the pitch suppression effects under environmental loads (wave height, wave period, wind thrust) and structural parameters of FOWT (column-deck spacing, ballast mass, tower height). The results indicate that gyro stabilizers generate positive damping at wave frequency and negative damping at low frequency. Both damping components increase with the wave height and period, but positive damping escalates more prominently, achieving a 3-times enhancement in pitch reduction under wind-wave combined conditions. Wind thrust amplifies suppression effects until reaching a threshold (2.7 N). For the influence of structural parameters, larger column-deck spacing reduces positive damping at wave frequency while increasing low-frequency negative damping, leading to diminished overall suppression. Additional ballast mass weakens positive damping by 77 %, and tower height elevation slightly enhances the promotion effect of wind load on the active damping at wave frequency, due to increased pitch angular velocity.
期刊介绍:
The aim of Applied Ocean Research is to encourage the submission of papers that advance the state of knowledge in a range of topics relevant to ocean engineering.