Abstract: Hydrodynamic load constitutes a critical parameter in the design of offshore aquaculture cages. However, the current severe deficiency in research on the hydrodynamic characteristics of flow-diversion and drag-reduction cage systems significantly constrains their safety design and structural optimization. This study systematically analyzes the influence of common offshore aquaculture cage geometry, net solidity, and inflow velocity on hydrodynamic loads based on physical model experiments. The experiment measured the hydrodynamic loads on square, hexagonal, octagonal, dodecagonal, and circular cages under steady flow conditions (flow velocity range: 0.3 m/s to 0.7 m/s at 0.1 m/s intervals). The results demonstrate that hexagonal cages exhibit significant flow-diversion and drag-reduction performance under both constant and varying conditions of net solidity and flow velocity. Under identical net configuration conditions, the mean hydrodynamic loads and their sensitivity to flow velocity across various cage types exhibited the following increasing order: hexagonal < octagonal < circular < square < dodecagonal. Among them, the hexagonal cage demonstrated approximately 78% of both the hydrodynamic load and flow-velocity sensitivity compared to the square cage. This study provides critical reference data for structural optimization of aquaculture net cages.

Key words: cage geometry, flow-reduction effect, flow velocity, net solidity, aquaculture cages, hydrodynamic characteristics;

摘要： 水动力荷载是深远海养殖网箱设计过程中重点关注的参数，但目前针对分流减流型网箱水动力特性的研究严重不足，制约了网箱的安全设计与结构优化。本研究基于物理模型试验，系统分析了常见的深远海养殖网箱结构形状、网衣密实度以及来流速度对网箱水动力荷载的影响规律。试验在定常流条件下（流速范围0.3 ~0.7 m/s，间隔0.1 m/s）测量了4、6、8、12边形及圆形网箱的水动力荷载。结果显示：无论在恒定或变化的密实度、流速条件下，六边形网箱的分流减流效果均为显著。在相同网衣设置条件下，各类网箱水动力荷载的均值以及荷载对流速的敏感性呈现以下递增规律：六边形<八边形<圆形<四边形<十二边形。其中，六边形网箱的水动力荷载及其对流速的敏感性均为四边形网箱的78%左右。本研究为养殖网箱的结构优化提供了参考。

关键词: 网箱形状, 减流效应, 来流速度, 网衣密实度, 深远海网箱, 水动力特性