Dynamics of dual pontoon floating structure for cage aquaculture in a two-dimensional numerical wave tank

The trend of using floating structures with cage aquaculture is becoming more popular in the open sea. The purpose of this paper is to investigate the dynamic properties of a dual pontoon floating structure (DPFS) when attached to a fish net by using physical and numerical models. A two-dimensional (2-D) fully nonlinear numerical wave tank (NWT), based on the boundary element method (BEM), is developed to calculate the wave forces on the DPFS. The wave forces on a fish net system are then evaluated using a modified Morison equation. The comparisons of dynamic behaviors between numerical simulations and experimental measurements on the DPFS show good agreement. Results also display that a fish net system causes the resonant response of body motions and mooring forces to be slightly lower due to the net's damping effect. Finally, for designing the rearing space of cage aquaculture, the influences which net depth and net width have on the DPFS dynamic responses are also presented in this paper.

► A dual pontoon floating structure (DPFS) attached with a fish net is investigated by using physical and numerical models. ► A two-dimensional fully nonlinear numerical wave tank, based on the boundary element method, is developed to calculate the wave forces. ► The wave forces on a fish net system are evaluated using a modified Morison equation. ► Results show that a fish net system causes the resonant response of body motions and mooring forces to be slightly lower due to the net's damping effect.