The Design Of Flexible Floating Reef And Its Hydrodynamic Characteristics Analysis

The world’s Marine fishery resources has reached the limit of catch. Manageability of fishery resources will be the main development direction of Marine fisheries in the new century, from the perspective of the development trend of modern fisheries.Marine ranching is one of the main methods of Marine resource management. Marine ranching system technology mainly include controlling technology of Marine biological resources, ecological environment controlling technology and support technology of resource production. Reefs is the key in the construction of a Marine ranching. Artificial reefs can form local upwelling, promote water exchange and increase the output of basic Marine resources. The range of bottom reefs action is restricted by their height. Marine ranching can only be played in offshore shallow water, not make full use of the upper waters, so the vast deep ocean area is difficult to construct marine ranching. In order to overcome the limitation of the depth of the water and the increase of the development and utilization of the upper waters of the underlying reefs, designed and developed a kind of flexible float reefs which can be put in any depth.This fish reef is composed of three fish reef module, designing the flexible floating fish reef structure from the mechanism of the reefs. food is the most important factor for fish reefs attracting fish, draw lessons from kelp and other algae cultivation technology, designed the algal reefs on which can grow algae. Algal reefs deployed in the top of the flexible floating fish reef, so the algae can receive sufficient sunshine, increase production of seaweed, release more oxygen, at the same time, floating algae can also provide shade for the fish. Algal reefs of nylon rope can also provide spawning ground for some biology needing long and thin shape spawning areaArtificial reefs can change the flow field in the sea state, promote the exchange of the water. Design the converter reefs, it uses the bell mouth bend as function unit. It can form the downward flow, bring the upper sea water rich oxygen and algae to the lower water layer, at the same time, stirring the nutrient at the bottom to the upper waters layer. Bell mouth bent pipe inlets toward four direction, so the different directional ocean current can enter the reef body.Reefs can offer fish shelter, to attract some of the fish into the reef body. Especially for parent fish and young fish, they all need a safe, tranquil flow area. The young fish growth and egg hatching area, Also requires that the water has good liquidity. Designed a kind of plate type reefs can provide conservation places for young fish, circular tube densely arranged structure of narrow space, the side hole of the circular tube increase the permeability, in the slip slope slowing trend is obvious.In order to verify the flow field characteristics of reef, do a numerical simulations of the converter reefs and plate type reefs about the flow field performance. Calculation results show that the converter reef has an obvious effect on the surface of slip slope, also has obvious effect for on top and bottom of the reef, outlet speed has quickened significantly. On the inside and slip slope of bell bend the current speed slowed significantly, and the emergence of the vortex. Plate type reefs has an obvious effect trend of slow, circular tube between the flow speed, pipe internal opening velocity faster, other position slowly. To speed up the pace and side make it has the good permeability.Finally this paper introduces the test of the flexible floating fish reef playing. Making three flexible floating reefs and playing in Xiangshan bay, to see reefs the morphology in the water and the reliability of the moored system. Designing underwater observation system and fixed to the reefs, to observe fish gather around the reef. Experimental results show that all kinds of performance of the reefs meet the requirements, and has a good aggregation for fish.