HYDRODYNAMIC PERFORMANCE OF A NOVEL MULTIFUNCTIONAL FLOATING OFFSHORE WIND TURBINE PLATFORM WITH HEAVING PLATES UNDER EXTREME SEAS

This work investigates the hydrodynamic performance of a novel multifunctional floating offshore wind turbine (FOWT) platform, designed to host multiple marine renewable energy technologies, developed by the National Research Council of Italy (CNR) and Fincantieri. The platform, adopts a caisson-type hull with triangular side and bottom openings to minimize hydrodynamic loading while promoting complex wave–structure interactions. A physical model campaign at a 1:60 scale was conducted in a laboratory wave flume to assess the platform response under irregular sea states corresponding to extreme conditions (50-year and 500-year return periods). Two configurations with and without flat heave plates (FP and W/O) were tested as shown in Figure 1. Motions and mooring loads were measured to assess oscillatory responses and mean drift effects. Free-decay analysis provides natural periods, equivalent damping, and amplitude-dependent variations, revealing that FP strongly enhance heave and pitch stability while producing mixed effects in surge. Irregular wave tests under extreme sea states show that FP increase effective damping in heave and pitch but can amplify surge motions, affecting RMS levels, total energy, and potential mooring loads.