Hydrodynamic And Experimental Study Of Coupling Floating Breakwaters With Wind Turbines

In the field of breakwaters,floating breakwaters have many advantages over fixed ones,such as their low construction cost and short construction period,their ability to resist water pollution and their high tolerance to the environment,making them suitable for offshore ports and all types of deep water.As a non-polluting renewable resource,wind power plays an important role in protecting the ecology and adjusting the energy structure,and is increasingly favoured by the market because of its short construction period,environmental benefits and flexible layout.China is located in the monsoon climate zone,the sea is rich in wind energy resources,offshore wind power development potential is huge,so the design of a floating breakwater and wind turbine integrated device in the field of engineering research has certain significance and research value.This thesis presents a design solution for an integrated device that uses a floating breakwater as a base and combines the characteristics of a floating wind turbine.The design solution selects a floating breakwater as the floating body structure and a full-size wind turbine as the generator set.Based on the Yeason-Momentum theory,three-dimensional potential flow theory and slender elastic rod theory,a wind-wave coupled time-domain numerical analysis model of the integrated device and its mooring system is established,focusing on its motion response and power generation under normal operating conditions.The main research work of this thesis is as follows.(1)To improve the understanding of the expected sea area,to determine the typical wind and wave conditions of the sea area,to initially confirm the conceptual design scheme of the integrated device of floating breakwater and wind turbine,to carry out the overall design of the three main components of the integrated device and to briefly introduce the working principle of this integrated device.(2)The theoretical and numerical methods of the wind-wave coupled time domain numerical analysis model are introduced in detail.The numerical analysis model is mainly based on the lobe element-momentum theory,three-dimensional potential flow theory and slender elastic rod theory.The simulation results were compared with the theoretical data from the literature,and the aerodynamic force,kinematic response and power generation were verified.(3)Coupled computational simulations were carried out on the design of the integrated device proposed in this thesis,and a time domain numerical analysis model of the integrated device and its mooring system was established to analyse its hydrodynamic performance,wave dissipation performance and power generation performance,and to compare its hydrodynamic performance and power generation performance with the OC4 floating wind turbine,and its wave dissipation performance with the floating breakwater without the wind turbine.(4)An experimental model of the integrated device was designed in accordance with the similar theory,and model tests were carried out in a two-dimensional tank under typical wind and wave conditions to investigate the hydrodynamic and wave dissipation performance of the integrated device,and the test results were analysed.The numerical simulation results show that the proposed integrated device has good wave resistance in vertical,longitudinal and longitudinal swell,and good wave dissipation performance,and the design is feasible.Compared to mainstream floating fans,the device allows the cost of floating breakwaters and floating fans to be shared,reducing costs while providing a dual function.