Hydrodynamic responses of an aquaculture cube net cage suspended inside a jacket foundation for various net solidities and bottom weights

The wind-aquaculture integration structure offers significant potential for marine resource use and is gaining increasing attention from academia and engineering community. This study introduces an innovative integrated structure called JOWT-AC, which suspends a net cage within a jacket structure. Based on the lumped-mass method, a cube cage is established within the internal space of the jacket. The contact interaction between the net and the jacket is considered by introducing a penetration model. Based on previous research findings and 1/25 scale flume experiments, the accuracy of the cage motion and tension was validated. The results show that as the current velocity increases, the cage state can be categorised into three stages: the safe aquaculture regime, the square bottom ring contact regime, and the cage unbalance regime. When the net solidity is between 0.12 and 0.20, the cage becomes unbalanced at a current velocity of 1.2 m s⁻¹. When the bottom weight ranges from 1000 to 1600 kg, the current velocity at which the cage becomes unbalanced varies. The increase of the bottom weight can effectively enhance the cage's ability to resist unbalance. The research results can provide valuable support for integrated systems design of jacket structure and cage.