Study On Hydrodynamic Performance Of A Novel Floating Breakwater With Multi-rigid Body System

In recent years,breakwater,as an important wave control technology and equipment,has been widely concerned by scholars at home and abroad,with the continuous development of wave damping technology,floating breakwater technology is more favored by scholars than the traditional sitting bottom breakwater.Due to the fundamental difference between the construction method of floating breakwater and traditional breakwater,the gap in wave damping performance,and the increasing demand for configuration with excellent wave damping effect in the field of marine engineering,people have been studying and designing floating breakwaters with better wave absorption performance and hydrodynamic performance,and the research on the main configuration,link mode,mooring mode and arrangement of floating breakwater has developed rapidly.At present,researchers mostly carry out the research on the configuration of floating breakwaters such as reflection type,broken type and friction type,and the research methods and wave absorption effect of floating breakwaters with multi-rigid articulated combination have been carried out less,and the coupling law of waves and multi-rigid bodies has not yet been explored.In this thesis,the hydrodynamic performance of the multi-rigid articulated floating breakwater is studied by numerical calculation method,taking the wave suppression of offshore operation as the engineering application background,taking the new floating breakwater with multi-rigid body articulated type as the research object.This thesis first starts from the structural design and mooring mode of floating breakwaters,and summarizes the research progress of domestic and foreign scholars on the performance of floating breakwaters from three aspects: experiment,theory and numerical aspects.Through the study of the traditional square box floating breakwater,a new floating breakwater configuration based on the multi-body coupling motion theory is proposed.Based on the finite volume method,a numerical calculation model for the analysis of the wavebreaking performance of the floating breakwater was established,and the accuracy of the numerical calculation method was verified by model experiments.On this basis,the hydrodynamic performance and wave damping performance of the new floating breakwater are analyzed by numerical solution of different multi-body coupling floating breakwater configurations under the action of regular wave.In this thesis,a multi-rigid body coupling breakwater design method is established on the basis of the square box type,and a multi-rigid body coupling model is designed by coupling the square rigid body and the breakwater body through rotating joints.The numerical calculations of the single-module multi-body articulation model and the multi-module multi-body articulation model respectively show that due to the coupling motion of the new breakwater internal multi-system,the dissipation of incident wave energy is intensified,and the wave absorption performance of the breakwater is significantly improved,and the sideways,rolls and vertical amplitudes of the breakwater are also smaller than those of the traditional floating breakwater.By changing the cross-sectional shape below the draft of the square body articulated model,the U-shaped body and semi-elliptical body articulation model are designed,and the calculation and summary of three different articulated configurations of breakwater with wave parameters,the wave absorption performance and hydrodynamic response of multi-rigid body articulated floating breakwater,and the change law of the number of intermediate articulated rigid bodies and wave damping performance,which provides technical support for the design and engineering application of floating breakwater.