Investigation of the effect of sloshing in a floating closed fish farm

In this thesis, the effect of sloshing on the dynamic response of a floating closed containment system(FCCS) has been investigated. Results from the SINTEF OCEANS experiment SJØFLO have been examined and compared to numerical calculations obtained from the potential theory solver WADAM by DNVGL. In the experiment, circular cylindrical models were subject to regular wave loads, and the degrees of freedom considered were surge, heave, and pitch. The reason for why FCCSs are being developed is that the costs related sea-lice infections in the salmon farming industry have grown tremendously over the past decade. One of the solutions to this problem is FCCS, where the farmer gets more control over the production environment. However, the FCCSs are distinctively different to the open net pen cages used in the industry today, and they pose new challenges that must be studied further to ensure that the FCCS is safe to operate and can maintain required conditions for fish well-fare. Results show that the effect of sloshing on the dynamic response in surge and pitch is significant. However, no clear effect of sloshing was found in heave motion. The potential theory results show the same pattern, with significant effects of sloshing in surge and pitch, and no effect in heave. The results obtained in this thesis coincide with the results obtained in the end report of the SJØFLO experiment. However, as the numerical calculations have been done with different software, some deviations are present. Finally, a spherical model was made in WADAM and analyzed for different filling levels. This analysis was done to see what effects changing filling levels of a floating structure have on the dynamic response. WADAM seemed to struggle with this type of structure, and the system was not stable until the floating collar was increased by a tenfold. Thus, care should be taken when comparing the results for the spherical model to the cylindrical one