Numerical simulation of a self-submersible SPM cage system in regular waves with following currents

Abstract

In response to the increased demand for food in general and food fish in particular, offshore mariculture is faced with the technological challenge of providing a viable cage design concept that is able to function effectively in high-energy environments. The single-point-mooring (SPM) fish cage systems for offshore fish farming are gaining support due to their environmentally friendly and economically favorable characteristics. An SPM self-submersible cage design concept has been identified as a potential mariculture cage concept for offshore waters, and the success of this concept depends on the operational performance in the offshore environment. Therefore, the current paper investigates the submergence characteristics of such a cage system in regular waves with a following current. This work also investigates the possibility of manipulating the cage system to achieve the desired submergence under different environmental conditions. The analysis demonstrates good potential for the self-submersible SPM cage concept in the simulated load cases because the response of the cage system to increasing wave height implies considerable additional submergence for realistic environmental conditions in offshore sites. The results also suggest that the concept allows adequate flexibility for use of the cage system in a range of environmental conditions.