Abstract
The growing global demand for renewable energy has accelerated the development of floating hybrid energy systems. However, their dynamic behavior under freak waves remains insufficiently understood. To maximize energy extraction in deep-sea environments, this study proposes a novel floating wind-wave-tidal (WWT) hybrid energy system optimized for efficient, integrated power generation. Systematic wave flume experiments are conducted to evaluate the system's behavior under regular, irregular, and freak waves. To quantify the advantages of the WWT system, a comparative analysis is performed against a conventional floating offshore wind turbine (FOWT). The results indicate that the WWT system effectively mitigates wave-induced resonance. Compared to the FOWT, the WWT system reduces pitch amplitudes under regular waves at the heave and pitch natural frequencies by 70.2 % and 94.6 %, respectively. The reduction in WWT pitch amplitude across different spectral peak periods reaches up to 37.12 %. Remarkably, under freak waves, the WWT system achieves a 44.7 % reduction in maximum pitch angle, further validating its robustness in extreme environments. Nonlinear vortex motion and restoring moments generated during the water entry and exit of wave energy converters (WECs) play a crucial role in stabilizing platform motion. As the first systematic experimental study on a WWT system under such diverse and extreme wave conditions, this work provides valuable insights into the design optimization of stable, high-efficiency hybrid energy systems. The findings underscore the potential of multi-source renewable energy systems to enhance offshore energy harvesting while ensuring operational reliability.