Effects of aquaculture cage on the dynamic response of an integrated structure consisting of a jacket offshore wind turbine and an aquaculture cage

This paper presents a fully coupled numerical investigation on a novel integrated system consisting of a 10 MW jacket foundation offshore wind turbine (OWT) and an aquaculture cage (JOWT-SC). An equivalent flexible bar model for the net is proposed using experimentally derived hydrodynamic coefficients, achieving satisfactory accuracy with errors below 4%. To quantify modeling uncertainties, comparative evaluations between the flexible and traditional rigid net models are conducted. The results demonstrate that although rigid net models overestimate local drag forces by 7%–10%, global response deviations remain below 1%. The flexible model is ultimately adopted for its dual advantages in capturing the actual net deformation and providing superior computational efficiency. Modal analysis and dynamic response simulations are carried out under typical load cases involving wind, wave, current and combined loads. Comparisons between the integrated structure and the jacket OWT reveal the significant effects of the aquaculture cage. The attached cage slightly reduces the high order natural frequencies and strengthens dynamic coupling between the rotor nacelle assembly and the pile foundation. Under normal wave and current conditions, additional damping introduced by the cage alleviates tower responses, whereas the pile foundation shear force is increased considerably. Under extreme combined loads, the mean pile foundation shear force increases to 2.98 times relative to the jacket OWT, and the net contributes dominant hydrodynamic loads. This study provides a reliable modelling approach and key dynamic characteristics for the design and analysis of wind-aquaculture integrated structures.