Effects of waves and currents on gravity-type cages in the open sea

• Published in: Aquacultural engineering Vol. 38; no. 2; pp. 105 - 116
• Main Authors: Huang, Chai-Cheng, Tang, Hung-Jie, Liu, Jin-Yuan
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2008; [Amsterdam]: Elsevier Science; Elsevier Science
• Subjects: algorithms; Animal aquaculture; Animal productions; aquacultural engineering; Biological and medical sciences; equations; equipment design; equipment performance; fish cages; fish farms; fish nets; Fundamental and applied biological sciences. Psychology; General aspects; hydrodynamics; mariculture; Marine; mathematical models; Mooring line tension; Net cage; Oblique waves and currents; Volume reduction coefficient; water currents; Taiwan; Net cage; Volume reduction coefficient; Oblique waves and currents; Mooring line tension; Cage; Aquaculture; Gravity; Environmental engineering
• ISSN: 0144-8609; 1873-5614
• DOI: 10.1016/j.aquaeng.2008.01.003

The effects of waves with a uniform current on marine aquaculture gravity-type cages were analyzed using a numerical model previously validated by physical model tests. The present analysis employs a numerical algorithm to study the dynamic behaviors of the net-cage system when impinged upon by surface waves from various angles over a uniform current. The maximum tension of the mooring lines and the minimum volume reduction coefficients of the rearing system were analyzed. We found that the current-induced effects on the net-cage system were more important than those due to waves only. We conclude that farming sites should not be situated in areas where the current speed exceeds 1 m/s, unless technological devices are available to overcome serious net-cage volume deformation. Furthermore, we recommend that, whenever possible, the combined effects of various oblique waves and currents be carefully examined before a system is installed. Finally, the ideal range of water depth for net-cage implementation in the open sea is between 30 and 50 m.