Numerical Analysis of a Floating Fish Cage With Feeding Systems

Abstract

A modern marine-based fish farm normally consists of a feeding barge, several fish cages, and feeding tubes. Although many studies, both experimental and numerical, are available in the literature to investigate the global responses of the fish cages under wave and current conditions, research on the coupled system including both the fish cage and the feeding system is very limited. This paper presents a numerical study on the coupled system with a floating fish cage and the feeding system. The purpose is to study the dynamic responses of the coupled system under different environmental conditions and configurations of the fish farm. A numerical model is firstly established in the numerical program OrcaFlex, comprising of a feeding barge, a gravity-based floating fish cage with mooring systems, and a feeding tube between the barge and the cage. Time-domain simulations of this coupled system are then performed under environmental conditions corresponding to 1-year and 50-year return periods for a reference site. The deformation of the fish cage, the tensions in the anchor lines and in the feeding tube are compared under various conditions. Sensitivity studies on the solidity ratio of the fish net as well as the lengths of the feeding tube are addressed, and their influences on the responses of the coupled system are also discussed.