Integration of oscillating water column wave energy converter into an aquaculture system: Numerical investigation of hydrodynamic interactions

• Directly integrated OWCWEC with semi-submersible aquaculture: unified hybrid system. • Hydrodynamic response analyzed pre/post hybridization under regular waves. • Initial investigation into the impact of bottom configuration on floating OWCWEC. • OWCWEC power influenced by bottom configuration; peak at 30° bottom inclination. • OWCWEC reduces surge motion, leading to 33.56% and 36.85% spring tension reduction. The expansion of offshore aquaculture into deep-water areas is hindered by energy supply limitations, as conventional diesel-powered systems suffer from high fuel transport costs, and greenhouse gas emissions. Wave energy offers a promising alternative; however, existing W ave E nergy C onverters (WECs) have high capital costs and limited suitability for harsh offshore environments, particularly when integrated with aquaculture platforms via mechanical connectors, flexible cages, or mooring-based coupling. This study presents the evaluation of the hydrodynamic behavior of the first direct integration of an O scillating W ater C olumn (OWC) WEC with a steel semi-submersible aquaculture cage to form a single unified body without any intermediate connectors. A RANS–VOF numerical framework was developed, incorporating an advanced forcing zone method and discretized by the finite volume method, to simulate the dynamic response of the hybrid system under regular waves. The influence of the OWC bottom configuration was quantified by varying the bottom inclination angle, representing the investigation of bottom-slope effects on a floating OWC–WEC integrated with an offshore aquaculture cage. The results indicate that adapting the OWC–WEC design parameters enhances power output and damps platform motion, thereby improving offshore survivability. Furthermore, the optimized design increases energy conversion efficiency, supports economic feasibility, and provides a robust foundation for the development of integrated offshore aquaculture–wave energy systems.