规模化透水性人工鱼礁阻流效应的数值模拟  

Numerical simulation of the flow retarding effect of large-scale permeable artificial reefs

作　　者：杨伟 林军 唐建江[3] 杨冠林 YANG Wei;LIN Jun;TANG Jianjiang;YANG Guanlin(College of Marine Ecology and Environment,Shanghai Ocean University,Shanghai 201306,China;Engineering Technology Research Center of Marine Ranching,Shanghai Ocean University,Shanghai 201306,China;East China Sea Forecasting Center,State Oceanic Administration,Shanghai 200136,China)

机构地区：[1]上海海洋大学海洋生态与环境学院,上海201306 [2]上海海洋大学海洋牧场工程技术研究中心,上海201306 [3]国家海洋局东海预报中心,上海200136

出　　处：《水产学报》2022年第12期2366-2382,共17页Journal of Fisheries of China

基　　金：国家重点研发计划(2019YFD0901302);中国海油公益基金会项目。

摘　　要：为在大尺度海洋模型中合理体现透水性人工鱼礁组合,基于海洋数值模型(FVCOM)模拟了大陈岛拟建人工鱼礁区的水动力情况,比较了阻滞力法、实心礁法和附加底摩擦法在投礁前后的垂向流速、礁顶平面流速、水体向上输运通量和背涡流体积的差异,并根据投礁前后的流速差异,应用经验公式预测了投礁1年后底床泥沙冲淤情况。数值模拟结果显示,同未设置礁体相比,阻滞力法体现的鱼礁在所占水层内流速最大减少了0.06 m/s,迎流面垂向上产生的上升流流速最大为0.005 m/s;涨急时刻礁体背面的流速减小范围可达礁体组合长度的20倍以上,对应流速减小海域一年后底床淤积厚度最大约0.05 m;单个台礁平均向上水体输运通量为66 m^(3),背涡流体积为1550 m^(3)。相较于实心礁法和附加底摩擦法,阻滞力法能很好体现礁体对水流的阻滞作用,避免了实心礁法在透水性鱼礁模拟中过高估计流场效应的问题,且无附加底摩擦法只适用于低矮礁体的缺陷。阻滞力法不仅适用于置底型透水性鱼礁,也适用于浮鱼礁和网箱等增养殖设施的水动力学和生态动力学研究。Artificial reefs can be regarded as artificial structures in the sea.There are three methods to reflect bottom structures in large-scale ocean models:method of water depth modified treats artificial reefs as impermeable solids and reflects reefs by changing the water depth,which is applicable to impermeable reef mountains;method of bottom friction increased reflects the obstruction of water flow by structures on the seabed by increasing the bottom friction of the model,which is applicable to the simulation of submarine mussel beds and low oyster reefs;method of retarding force simulates the obstruction of water flow in different water layers by adding a retarding force term to the model momentum equation.In order to reasonably represent the permeable artificial reef assemblage in the large-scale ocean model,the hydrodynamic conditions of the proposed artificial reef area on Dachen Island were simulated based on the numerical ocean model FVCOM(An unstructured grid Finite-Volume Community Ocean Model),and the differences of vertical flow velocity,reef top plane flow velocity,upward transport flux and back eddy volume before and after reefing were compared among the method of water depth modified,method of bottom friction increased and method of retarding force.Based on the difference of flow velocity before and after reef casting,the empirical formula was applied to predict the bottom bed sediment flushing and siltation one year after reef casting.The numerical simulation results showed that by adding the retarding force term in the model,the flow velocity in the occupied water layer was reduced by 0.06 m/s compared with the time when the reef was not installed,and the maximum upward flow velocity was 0.005 m/s in the direction of incoming flow;the reduction of flow velocity at the back of the reef at the time of rapid rise can be more than 20 times of the combined length of the reef,and the maximum thickness of the bottom bed siltation after one year in the corresponding flow velocity reduction sea was about 0.05

关 键 词：人工鱼礁 透水性 海洋数值模型(FVCOM) 阻滞力法 底床冲淤 

分 类 号：S953.1[农业科学—水产养殖]