Sloshing dynamics of a tuned liquid multi-column damper for semi-submersible floating offshore wind turbines

In this paper, sloshing inside a novel passive control device termed tuned liquid multi-column damper (TLMCD) for mitigating rotational motions of semi-submersible floating offshore wind turbine (FOWT) is numerically modelled using high-fidelity CFD approach. Test cases the under various external excitations including single degree surge and pitch as well combined surge/pitch are presented analysed to reveal its damping mechanisms performance. Through analysing results predicted induced moments on TLMCD structure their phases range excitation frequencies, it was found that although maximum always occur at or very close resonance excitations, may not be exactly opposite those wave-induced FOWT platform, which has important implications optimal design system applications. The study also shows performance significantly affected by change relative angular (yaw) position would potentially more robust than traditional U-shaped TLCDs, applied in isolation combination.