A tuned liquid damper (TLD) is one of the most economically passive vibration control strategies for controlling the wind-induced vibrations of structures such as wind turbines (WT). The literature on fluid-structure interaction limits the scope of analysis to either the influence of wind on tower, or liquid on tank. Meanwhile, it does not consider the applicability of damper installation inside the tower or even inside the nacelle. This study adopts an integrated experimental and numerical approach to find an applicable TLD configuration to mitigate vibrations of a 5-MW wind turbine considering the mutual effects between wind, tower, and liquid damper. It uses the Ansys Fluent module in the tower's TLD and wind-induced vibrations. It starts with wind load simulation, including the vortex shedding effect. Then, it presents the sloshing water behavior and validates it with an experimental model. Parametric study has been conducted to consider the effect of different mass ratios, frequency ratios, and the influence of soil stiffness on the response on the WT tower. The experimental analysis demonstrates TLD's feasibility in mitigating vibration sufficiently with a 40% displacement reduction. A single TLD with a 4% mass ratio can reduce the lateral deformations by 7.32 and 12.5% of WT with fixed and partially fixed end conditions, respectively. While using a configuration of 3 TLDs with a 12% mass ratio extends the fatigue life by 38% and offers a gain in lateral deformations reduction that reached 48.73 and 71.45% for both fixed and partially fixed end conditions.

In recent decades, research on renewable energy has been boosted by the emerging awareness of energy security and climate change and their consequences, such as the global cost of adapting to the climate impacts. Both onshore and offshore wind turbine farms have been considered as one of the main alternatives to fossil fuels. Their development currently involves seismic-prone areas, such as the Californian coastline and East Asia, where the risk of soil liquefaction is significant. Onshore wind turbines (OWTs) typically are founded on shallow rafts. Their operation can be affected strongly by the simultaneous presence of intense earthquakes and wind thrust, which may cause remarkable permanent tilting and loss of serviceability. In these conditions, accurate evaluation of the seismic performance of these structures requires the development of well-validated numerical tools capable of capturing the cyclic soil behavior and the build-up and contextual dissipation of seismic-induced pore-water pressures. In this paper, a numerical model developed in OpenSees, calibrated against the results of dynamic centrifuge tests, was used to evaluate the influence of some ground motion intensity Measures of the seismic behavior of OWTs included the amplitude, frequency content, strong-motion duration, and Arias intensity (energy content) of the earthquake, together with the effect of a coseismal wind thrust, which is not well explored in the literature. The seismic performance of an OWT was assessed in terms of peak and permanent settlement and tilting, the latter of which was compared with the threshold of 0.5 degrees typically adopted in practice.