Numerical investigation on the hydrodynamic behaviour of a wind-solar-aquaculture integrated floating structure

To address the challenges of spatial competition, high construction costs, and cumulative environmental impacts associated with traditional single-function offshore resource development, this study proposes an innovative wind-solar-aquaculture integrated structure named “AquaEnergy”. The system integrates floating offshore wind turbines, aquaculture cages, and floating photovoltaic panels within the same marine area, enabling the synergistic development of renewable energy and aquaculture while promoting green and low-carbon utilisation of ocean resources. A three-dimensional numerical model of dynamic response was developed, incorporating the wind turbine, photovoltaic structure, net cage, and mooring system. By conducting a comparative analysis of the time-domain response characteristics under different structural configurations, the effects of drag force, photovoltaic system, and net solidity on the platform’s motion, line tension, and power generation performance were investigated. The results indicate that the introduction of drag force significantly increases the system’s energy dissipation, leading to a faster decay of oscillations in the decay curve. The presence of the net primarily enhances the system damping. The PV system has no significant effect on the damping or decay period of each degree of freedom. Increasing net solidity has a minor effect on the wave-frequency responses of surge, heave, and pitch motions of the platform. However, it enhances the wave-frequency response of the windward line tension and weakens that of the leeward line. This study provides a theoretical basis and engineering reference for the design optimisation and safety evaluation of multi-functional, complementary, integrated “wind-solar-aquaculture” floating platforms.