A Two-Dimensional Approximation of a Floating Fish Farm in Waves and Current With the Effect of Snap Loads

Wave and current loads on the floater, netting and sinker tube of a floating fish farm are discussed. High flexibility of netting, floating collar and sinker tube and their structural interaction are important effects. Regular wave and uniform current load induced response of a section of a floater with net structure and sinker tube are analyzed experimentally and numerically in order to simplify the problem. The sectional models of the floater and the sinker tube are considered rigid. Experiments were done in a wave flume with model scale 1:10 for three net solidity ratios (Sn) and three sinker tube weights. Hydrodynamic loads on the net structure and its motion are calculated based on the screen force model proposed by Kristiansen and Faltinsen [1] and are coupled with floater and sinker tube motions in a time domain simulation. Good agreement is achieved in terms of net shape, tensions and floater motions. Large snap loads due to the elastic behavior of the net structure and the relative motion between the floater and the net are observed experimentally and predicted numerically. This type of cyclic loading has to be considered in terms of net structure failure.