Abstract: Fish cages composed of ropes and nets will suffer more severe marine environmental conditions in deep sea. In order to measure the maximum tension and normal displacement of the ropes corresponding to the net panel, a finite element method was proposed to evaluate the tension response of ropes by coupling the Morison models and Screen models to calculate the hydrodynamic forces on ropes and nets separately. The tension response of the ropes in two independent nets A and B at different water depths was studied under the pure current and wave-current interaction conditions. For pure current conditions, statistical analysis of the numerical results shows that the average maximum tension and normal displacement of the ropes are growing as the current grows. The average maximum tension and normal displacement of the ropes in net A were significantly larger than those in net B under the wave-current interaction conditions. The average maximum tension and normal displacement of the ropes decrease with the increase of the design wave period in net A, while the average maximum tension of network B increases gradually. This study will be useful for the research on the coupling of ropes and nets.

Key words: fish cages, ropes, nets, morison model, screen model, tension

摘要： 桁架式等深远海养殖网箱的养殖网由网纲和网衣组成，在无遮蔽海域将遭受更为严峻的海洋环境条件。为衡量承力网纲的最大张力与面法向偏移，采取一种耦合Morison模型和Screen模型计算网纲和网衣水动力载荷的有限元方法。以不同水深位置、上下相互独立的两片养殖网A和B为研究对象，开展网箱坐底时承力网纲在纯流、波流联合作用下的张力响应研究。对数值计算结果进行统计性分析发现，纯流条件下的网纲平均最大张力和面法向平均最大偏移随流速增加而增加；波流联合作用下养殖网A的网纲平均最大张力和面法向平均最大偏移随设计波周期的增加而减小，养殖网B则逐渐增加，总体上A的结果显著大于B。研究对网纲和网衣耦合的有关研究具有参考作用。

关键词: 养殖网箱, 网纲, 网衣, Morison模型, Screen模型, 张力