Wave-Induced Accelerations of a Fish-Farm Elastic Floater: Experimental and Numerical Studies

Numerical simulations and experiments of an elastic circular collar of a floating fish farm are reported. The floater model without netting structure is moored with nearly horizontal moorings and tested in regular deep-water waves of different steepnesses and periods without current. Local overtopping of waves was observed in steep waves. The focus here is on the vertical accelerations along the floater in the different conditions. The experiments show that higher-order harmonics of the accelerations matter. A three-dimensional (3D) weak-scatter model with partly nonlinear effects as well as a 3D linear frequency-domain method based on potential flow are used. From their comparison against the measurements, strong 3D and frequency dependency effects as well as flexible floater motions matter. The weak-scatter model can only partly explain the nonlinearities present in the measured accelerations.