Floating Wind Turbine Dynamic Response Considering Chain-Seabed Interaction in SIMA

Abstract Traditional integrated analyses of floating wind turbines (FWTs) commonly overlook the effects of embedded mooring line, which may increase uncertainties in mooring system design. A macro-model of chain-seabed interaction was introduced in the static mooring analyses for FWTs, but its impact under dynamic condition, involving time-varying environmental loads, remain unexplored. In this study, dynamic analyses of VolturnUS-S floater supporting the IEA 15MW FWT were conducted based on a macro-model of chain-seabed interaction in SIMA. Three typical cases were designed to investigate the dynamic responses of FWTs under operational condition with wind speed around turbine rated speed, focusing on the influence of embedded line. The mooring line response and floater motion were analyzed and compared. The results show that the embedded line influences the mooring system response of VolturnUS-S floaters supporting the IEA 15MW FWTs, particularly affecting line tension at the padeye. For fairlead displacement and tension, Cases 1 and 2, with the same mooring line length, show similar responses, while Case 3 differs significantly due to its shorter length. For padeye tension, Case 1 has significantly lower maximum and mean tensions than Cases 2 and 3, mainly due to seabed friction in the embedded line. This study evaluates the influence of embedded lines on the dynamic responses of floating wind turbines.