Experimental and numerical investigations of loads on aquaculture nets

Abstract

This master thesis is to investigate the drag forces on net panels with different twine diameter, material, solidity ratio, and Reynolds number. A series of net panel towing tests has been carried out. Resistance force on the net panel was measured. The nets have been tested in current only condition, wave only condition and current with wave condition with a representative range of current velocity, wave period and wave steepness. Error and uncertainty in the net panel towing test are analyzed in detail. Numerical simulations were implemented. The numerical simulation in this thesis is realized in the framework of the open source computational fluid dynamics toolbox OpenFOAM with version 4.1. The porous media model was proposed to solve the flow characteristics through and around a net panel. A variety of net panels with different solidity ratio from experiments are applied in the validation case. The porous resistance force was obtained fromnumerical simulation to comparewith the drag force in current only condition from experiments. Satisfactory agreement between simulations and experiments was demonstrated.