Experimental study on the hydrodynamic responses of a novel platform integrating vertical-axis wind turbine with a fish cage in regular waves

An offshore wind energy–aquaculture integrated platform, combining a floating vertical-axis wind turbine with a fish cage (VAWT-FC), is proposed in this study. To investigate its hydrodynamic response characteristics, laboratory experiments were conducted using a 1:100 scale physical model. Regular wave tests were performed to analyze the platform's behavior under various wave heights and periods. The results show that the heave, surge, pitch motions, and mooring line tension all increased with wave height. For instance, as the wave height increased from 3 cm to 12 cm, pitch motion increased from 3.17° to 11.70°, and mooring tension increased by 229 %. With increasing wave period, surge and heave initially decreased and then increased, while pitch showed the opposite trend. A critical inflection point was observed at a wave period of 0.8 s, where the pitch amplitude peaked and both surge and heave reached minimum values—corresponding to a wavelength approximately equal to the platform’s 0.851 m span. Furthermore, wave overtopping was found to occur in two distinct stages as wave height increased and in three stages as wavelength increased. In contrast, wave breaking was observed to evolve through two phases under the influence of both increasing wave height and wavelength. The findings offer valuable insights for the development and optimization of multi-functional offshore platforms integrating renewable energy and aquaculture.