advanced vibration control of a jacket-supported offshore wind turbine using a novel semi-active liquid column gas damper

The global transition towards renewable energy has underscored the importance of offshore wind turbines (owts), which face significant dynamic challenges from combined wind and wave loads. jacket-supported owts (jowts), while structurally efficient, possess low inherent damping, making them highly susceptible to vibrations that can compromise serviceability and long-term integrity. this study presents a comprehensive investigation into the application of a novel semi-active liquid column gas damper (salcgd) for mitigating the dynamic response of a 5 mw jowt. an integrated aero-hydro-servo-elastic simulation framework was developed, combining high-fidelity finite element modeling in sap2000 and abaqus with a dynamic simulink model. the model incorporates realistic wind loads simulated using the blade element momentum theory via fast/turbsim and wave loads derived from the pierson-moskowitz spectrum and morison's equation. the salcgd, positioned in the nacelle, features a controllable orifice whose head loss coefficient is dynamically adjusted in real-time using a bang-bang control algorithm based on the instantaneous velocity and displacement of the damper's liquid. its performance was rigorously benchmarked against an optimized passive tuned liquid column gas damper (tlcgd) and an uncontrolled base case across 29 distinct north sea environmental conditions. the results demonstrate that the salcgd consistently and significantly outperforms the passive system. under extreme operating conditions, the salcgd achieved peak reductions in nacelle acceleration and displacement of up to 51.8% and 47.6%, respectively, compared to the uncontrolled structure. compared to the passive tlcgd, the salcgd provided an additional 20-50% reduction in dynamic responses. parametric studies on damper mass and frequency ratios confirm the robustness of the semi-active control strategy. this study conclusively establishes the salcgd as a superior, adaptive solution for enhancing the dynamic performance and operational stability of offshore wind infrastructure, paving the way for more reliable and cost-effective wind energy generation.