Numerical evaluation on the flow field of an aquaculture vessel

Abstract

This study presents a numerical investigation of the flow field distribution of a large semi-submersible hybrid aquaculture vessel in uniform flow. A coupled numerical framework is developed to simulate viscous flow behaviour inside and around the vessel. The influences of three key factors, such as the existence of the fishing net, the net solidity and the net-to-truss spacing on the flow field distribution are evaluated. The results indicate that the presence and arrangement of the fishing net have a pronounced influence on flow velocity and flow-field uniformity. It suggests that a reasonable combination of net types can effectively reduce drag force and optimize flow uniformity around the aquaculture vessel. Net solidity should be optimised to ensure both structural stability and breeding environment quality. Furthermore, the net-to-truss spacing plays a relatively important role in the spatial distribution of internal flows. The research also demonstrates the role of the fore and aft buoyancy tanks in attenuating velocity and in vortex development within and around the aquaculture vessel. This study elucidates the flow-field characteristics under different net configurations, providing insights for the design and optimisation of fishing nets.