| China owns long coastline and is very rich in marine resources.In recent years,with the introduction of policies such as energy conservation and environmental protection and the increase in people’s demand for high-quality protein,the offshore wind power and far-reaching marine fisheries and aquaculture industry have developed rapidly,but the offshore fixed wind turbine and fishery aquaculture industry have almost reached saturation.Therefore,the offshore wind power and fishery aquaculture industry urgently needs to develop into the deep sea.At present,the state’s offshore wind power subsidy policy gradually declined and the installation and maintenance costs are high to make its development seriously restricted,the emergence of large-scale semi-submersible aquaculture cages makes deep-sea aquaculture possible,but its offshore distance is far from the cost of power supply,therefore,consider the rational development and utilization of marine resources,while avoiding the conflict between offshore floating fans and deep-sea aquaculture,the combination of offshore floating wind turbines and aquaculture cage structures is of great research significance.In this paper,a deep-sea semi-submersible cage and wind turbine integrated structure is proposed,and the research on this structure mainly includes two aspects: one is to study the motion characteristics of the structure and the anchor rope stress under different wave/flow conditions through physical model experiments;the other is to use the finite element method to conduct numerical simulation to study the force and motion law of the anchor rope under different mooring methods,the specific content is as follows:Firstly,the physical model of the deep-sea semi-submersible cage and wind turbine integrated structure was designed,and according to the size of the experimental tank,the 1:100scale and four-point anchoring form were adopted,and the common two mooring methods(tensioning and catenary)and 10 regular waves,9 irregular waves,4 pure currents,13 waves and flow,and 2 wind and wave currents combined working conditions were designed to simulate the actual sea conditions,and to explore the movement characteristics and anchor rope force of the structure in the two mooring modes under the simple wave action and joint action.The experimental results show that the tension anchor rope force is significantly greater than that of the catenary type,and the movement amplitude change trend of the structure under each working condition is similar under the two mooring methods,and the heave and surge are basically the same,and the pitch is not much different,so the mooring mode of the catenary has significant advantages.Secondly,the finite element model of the deep-sea semi-submersible cage and wind turbine integrated structure is established,which is verified according to the hydrodynamic response results of the regular wave conditions in the physical model test to show the reliability of numerical calculation,the amplitude of the structure and the force of the anchor rope without net are simulated,and the influence of different mooring angles on the anchor rope force is explored.The results show that due to the shielding effect and damping effect of the net,the tension value of the structural anchor rope with net is small,and the amplitude of motion is relatively small.The semi-submersible cage and wind turbine integrated structure proposed in this paper is a new design structure that combines a semi-submersible fan with a deep-sea steel structure semi-submersible cage.This new structure can effectively use marine space,achieve a win-win situation between the modern marine ranch industry and the clean energy industry,and is of great significance to social and economic development and environmental protection,and its experimental and numerical results can provide reference for related research. |
