布设间距对多孔方型人工鱼礁流场效应影响的数值模拟研究

采用计算流体动力学(CFD)技术,研究了不同布设间距下,多孔方型人工鱼礁周围水流运动的规律,旨在为深入研究人工鱼礁的集鱼原理和海洋牧场建设中人工鱼礁的投放和布设提供更多参考。本研究采用了4种布设间距,分别为0.5、1、1.5和2倍鱼礁高度,基于计算机数值模拟技术,模拟了速度为0.8m/s的水流流经2个礁体的过程,分别观察鱼礁周围水流运动情况。结果显示,多孔方型人工鱼礁内部和周围存在缓流区、背涡流区、上升流区、死水区等有显著特征的区域;多孔方型人工鱼礁上升流的最大速度与来流速度的比值约为0.95倍;多孔方型人工鱼礁周围上升流最大抬升高度与鱼礁高度之比约为2.1;多孔方型人工鱼礁的结构在一定程度上为鱼礁周围的流态多样性提供了较有利的作用;多孔方型人工鱼礁的布设间距对2个鱼礁单体间的旋涡数量和旋涡方向有较大影响,也对涡量大小和涡量分布范围产生影响。研究表明,在一定范围内,布设间距越大,涡量越大,分布范围越广,但超过一定范围后,涡量不再增大,分布范围也不再扩大;多孔方型人工鱼礁的布设间距越大,背涡流在X方向和Y方向的影响面积越大。研究结果清晰地展现了不同布设间距下的人工鱼礁的流场效应,对在特定条件下进行人工鱼礁投放和布设具有重要意义。

Numerical Simulation Study on Influence of Disposal Space on Effects of Flow Field Around Porous Square Artificial Reefs

In this study,computational fluid dynamics(CFD)technology was used to study the flow patterns around porous square artificial reefs with different disposal spaces.The aim was to increase our knowledge base of the fish harvesting principles of artificial reefs and the deployment and layout of the artificial reefs in the construction of marine pastures.Four kinds of disposal spaces were used in the study;they were 0.5,1.0,1.5,and 2.0 times the height of the reef.Based on the computer numerical simulation technology,the process of water flowing past the two reefs at a speed of 0.8 m/s was simulated,and the flow around the reef was observed.The results show that there were obvious characteristics of slow flow areas,back eddy current areas,upwelling areas,and dead water areas inside and around the porous square artificial reef.The ratio of the maximum upwelling velocity to the inflow velocity of the porous square artificial reef was about 0.95 times.The ratio of the maximum upwelling height to the reef height around the porous square artificial reef is about 2∶1.To some extent,the structure of the artificial reef provides a favorable role for the diversity of flow patterns around the reef.The spacing of the porous square artificial reef has a great influence on the number,size,distribution,and direction of vortices between the two reefs.Within a certain range,the larger the spacing,the larger the vorticity and the wider the distribution range.Beyond a certain range,the vorticity does not increase and the distribution range does not expand.The larger the spacing of the porous square artificial reefs,the larger the influence area of the back eddy current in the X and Y directions is.The results clearly show the flow field effects of artificial reefs with different disposal spaces,which is of great significance to the deployment and layout of artificial reefs under specific conditions.