水流条件下单点系泊不同结构“钻石型”重力式网箱的水动力特性数值模拟

Numerical Study on Hydrodynamics of Single-Point Mooring Different Structural Net of “Diamond Shape” Gravity Fish Cage in Current

目前深远海网箱养殖已成为我国海水鱼类养殖的一个重要方向,为获得适合于深远海养殖的最优网箱结构,本文利用数值模拟方法,对投放于黄海冷水团的"钻石型"网箱箱体设计了5种结构方案(方案1～方案5),进行水动力特性数值模拟,分析箱体结构的中部水平漂移、底部水平漂移以及网箱阻力等特性变化。研究表明,在流速为1m/s时,网箱中部水平漂移优化效果好的依次为方案5(减少30.59%)和方案2(减少20.23%),底部水平漂移优化效果好的依次为方案2(减少37.33%)和方案5(减少22.39%),网箱阻力优化效果好的依次为方案5(减少12.98%)和方案4(减少9.15%)。研究结果表明,采用刚性底框、方形网目,中部增加刚性圆环,网箱形状为上大下小的圆台形,有利于减小网箱的横向位移,降低网箱的阻力。研究结果可为深远海重力式网箱设计提供技术参考。

With the increasing demand for the high-quality fish protein and decreasing trend of marine fisheries,especially the exhausted coastal fishery resources,offshore fish farming industries develop rapidly and become an important research direction in Chinese marine aquaculture.We used numerical simulation to optimize the structure of a new-designed single-point mooring gravity fish cage,which is currently located in the cold-water mass in the Yellow Sea.In the optimizing process,we compared and analyzed the displacement of the middle part and bottom,and the drag force of different structures to find the optimal design.The result shows that at the velocity of 1 m/s,compared with case0,the maximum reduction of the displacement at the middle of the cage is case5(reduced by 30.59%)and case2(reduced by 20.23%),the maximum reduction of the displacement at the bottom is case2(reduced by 37.33%)and case5(reduced by 22.39%),and the maximum reduction of the total drag force is case5(reduced by 12.98%)and case4(reduced by 9.15%).The results suggest that adapting rigid bottom ring,squared mesh,middle reinforced ring,and coned shape could reduce the displacement and drag forces.The study could provide technical reference for the offshore gravity fish cage.