遮板型开孔式正方体人工鱼礁流场特性数值研究

Numerical study on flow field characteristics of a novice open-aperture square artificial reef with shutter

为开发一种能同时增殖鱼类与底栖生物的人工礁体,在山东省莱州湾明波海洋牧场无遮板正方体人工鱼礁的基础上,提出了一种遮板型开孔式正方体人工鱼礁。基于CFD仿真和波流动力学理论,采用Fluent软件分别对无遮板、遮板型不同开口比的正方体人工鱼礁的流场特性进行了数值模拟,比较了5种来流流速条件下两种不同结构礁体周围的上升流、背涡流及遮板以下区域的流场分布特征。结果表明:在不同来流流速条件下,遮板型开孔式正方体人工鱼礁在开口比为0.11时较其他开口比的礁体有更大高度的上升流、更大面积的背涡区及更大范围的顶部涡流,但开口比不会影响遮板以下缓流区域。在相同开口比、相同流速的条件下,遮板型开孔式正方体人工鱼礁能为底栖生物增殖创造更加适合的流场环境,同时能够更好地发挥鱼类增殖效果,开口比为0.11时的遮板型开孔式正方体人工鱼礁的效果最为显著。研究结果可为人工鱼礁的结构型式设计提供新的思路和参考。

In order to develop a type of artificial reef that is beneficial for the proliferation of both fish and benthos,a novice open-aperture square artificial reef with a shutter close to the bottom was proposed based on the open-aperture square artificial reef without shutter of Mingbo Marine Ranch in Laizhou Bay,Shandong Province.Based on CFD simulation and wave flow mechanics theory,Fluent was used to carry out numerical simulation of flow field characteristics of the square artificial reefs with and without shutter under different aperture opening ratios,and the flow field distribution characteristics of upwelling,wake vortex and areas under the shutter were compared under five conditions of inflow velocities.The simulated results showed that the novice open-aperture square artificial reef with shutter under the aperture opening ratio of 0.11 has a higher upwelling height,a larger area of wake vortex area and a wider range of upwelling than the reef bodies with other opening ratios,but the opening ratio does not affect the slow-flow area under the shutter.This novice artificial reef can create a better flow field for the proliferation of benthos,as well as promote fish proliferation under the condition of the same aperture opening ratio and flow velocity.The improvement effect is the most significant when the aperture opening ratio is 0.11.The research results can provide new ideas and guidance for the practical engineering of artificial reefs.