Effects of Design Factors on Drag Forces and Deformations on Marine Aquaculture Cages: A Parametric Study Based on Numerical Simulations

Abstract

In Japan, the marine aquaculture net cage has an important role in farming pacific bluefin tuna farming in oceans, and the design of the net cage needs to ensure robustness against hostile oceanic conditions. Accordingly, this study focuses on the drag forces and the cage volume of the net cage, and on their variations induced by different design parameters (netting solidity ratio, netting height, and bottom weight). A series of parametric studies on drag force and deformation of the net cage was conducted using a numerical simulation model. Accordingly, the contribution of each parameter to the drag and volume was analyzed using a generalized additive model. The results indicate that the bottom weight had the highest contribution to the holding ratio of the cage volume, whereas the netting height had the highest contribution to the drag coefficient of the net cage. Finally, a fast prediction model was created by a backpropagation (BP) neural network model and was examined for the accurate prediction of the objective variables.

Sinking Behavior of Netting Panels Made with Various Twine Materials, Solidity Ratios, Knot Types, and Leadline Weights in Flume Tank

“…Thus, the present study and that of Tang et al [1] demonstrated that the increasing leadline weight led to an increasing sinking depth and speed and a decreasing sinking time. Also, relevant studies such as Dong et al [23] in the flume tank demonstrated that the bottom weight (sinking depth) increased the sinking depth of the net cage, which agrees with the results obtained in the present study. Thus, it can be observed that in the case of purse seines, the improvement of the sinking performance of this fishing gear (more incredible sinking speed and depth) is achieved when the leadline weight (sinking depth) is higher.…”