Hydrodynamic analysis of wave and cylinder fish cage interactions

Abstract

Submerged net cages have been commonly used for offshore fish farming. The present study analyses the linear elastic behaviour of a cylindrical fish cage interaction with linear waves, based on the potential flow theory. The fishnet is treated as a porous membrane, therefore, Darcy's law is applied to deal with the pressure-velocity boundary conditions on the net interface. The flow field is divided into two regions where the scattered velocity potentials are solved by the Fourier-Bessel series and the least square approximation methods. Numerical results show that the higher amplitude of dynamic pressure difference acting on the net surface due to the wave is mainly concentrated on the upper part of the fish cage. The present study provides a feasible prediction of the wave action estimations and the dynamic response of the net cage structure, which are key factors for the design of the offshore fish cage.