The Characteristics Of The Flow Of Ship-shaped Artificial Reef And Its Relationship With The Behavior Of Fish Aggregation

In this paper,FLUENT area of large fluid software ANSYS WORKBENCH and particle image velocity(PIV)flume simulation experiment were used to study the flow field effect of artificial reef,in which simulation analysis was carried out on the artificial reef of single ship in different placement modes,and a series of indicators such as upwelling and back eddy were collected.And then feasibility analysis was carried out by PIV test.Meanwhile,the numerical simulation of monomer ship reef and monomer cube reef was compared by FLUENT.Then by FLUENT software,numerical simulation analysis was carried out on the single ship artificial reef in five ship hull width gradients(4m,5m,6m,7m,8m),three cabin height gradients of 3m,4m,5m)and three catamaran reefs with different combinations,and a series of indicators were analyzed.Next,the stereoscopic camera technology and analysis video surveillance were used to study and analyze the fish aggregation behavior,and the number,species and mantailings of the occurrence locations of fish around the ship reef in four seasons were integrated to analyze the changes of fish aggregation behavior with the flow field under the same tidal period.In addition,the changes of fish aggregation behavior at different time and place were analyzed by video surveillance on the seabed of wuzhizhou island.The results show that the simulation results of FLUENT model are reliable,and the study on the flow field of ship reef is more meaningful than that of other reef types such as cubic reef.Changing the width of ship hull and trying to arrange more ship reefs can produce better flow field effect on ship reef.The large velocity range at the bow of the ship provides guidance for fish aggregation,while the slow flow area at the stern of the ship and in the cabin is suitable for small fish to avoid predators and survive.According to the real-time monitoring of seafloor fish aggregation behavior,it can be seen that the number of seafloor fish aggregation at ebb tide is greater than that at high tide,and the tidal level will also affect the behavior of fish aggregation.