Numerical Simulation Of Hydrodynamic Characteristics Of Porous Floating Breakwater

Floating breakwater attracts wide attention because it will not increase the construction difficulty and cost due to the increase of water depth,and it has the advantages of enhancing the function of sea water exchange and protecting the environment.In this paper,the influence of different opening factors on the hydrodynamic characteristics of open-ended floating breakwater is discussed in order to provide basis for the design and practical engineering application of open-ended floating breakwater.Based on the boundary element method,this paper uses ANSYS AQWA software to conduct numerical simulation.Firstly,the transmission coefficient,motion response amplitude operator and mooring force of the floating breakwater are verified.Compared with the literature results,the error is within 10%,which proves that the numerical simulation results in this paper have certain accuracy.On the basis of the rectangular-pontoon floating,the paper analyzes the influence of different porous factors on the wave dissipation characteristics of the floating breakwater,proposes a kind of porous floating breakwater,and simulates the influence of different opening number,opening length,opening arrangement and opening shape on the transmission coefficient,motion response and mooring force of the porous floating breakwater under the action of regular waves.The calculation results of the transmission coefficient show that increasing the number of opening,the length of opening and the number of sides of the opening shape can improve the wave dissipation effect,and the wave dissipation effect of the cross arrangement is better than that of the parallel arrangement.The calculation results of the motion response show that the increase of the number of openings will increase the amplitude of heave and also slightly increase the natural period,which will reduce the sway and pitch displacement of the floating breakwater;With the increase of the opening length,the heave displacement of the floating breakwater will increase,and the pitch motion amplitude will decrease;The layout of openings has the greatest impact on pitch and the smallest impact on heave;The variation trend of the heave of the pentagonal and hexagonal perforated pontoons is basically the same,with little difference in values.The motion response in the heave direction of the triangle is the most severe,while the motion response in the sway direction of the quadrilateral perforated pontoons is the most severe.The calculation results of mooring forces show that the increase of the number of holes and the length of holes will reduce the mooring forces;The mooring force of parallel arrangement with opening is greater than that of cross arrangement;The maximum mooring forces of triangular,quadrilateral and hexagonal perforated pontoons are similar,while the mooring forces of pentagonal perforated pontoons are the lowest and the safety performance is the highest.