Research On Hydrodynamic Performance And Wave Force Of The Porous I-type Plate Composition Breakwater

With the large-scale port and the open utilization of coastal zone,porous I-type plate composition breakwater has the advantages of low cost,good water exchange,good adaptability of soft foundation,convenient and efficient construction and so on.Therefore,it is of great significance to study it.In this paper,the numerical wave-making flume is established to study the hydrodynamic performance and wave force of porous I-type plate composition breakwater under regular wave action by means of the numerical simulation software Flow-3D.The hydrodynamic performance of I-type plate composition breakwater under the above factors were analyzed by taking A/Ao,j/L,d/L,H/L and h/d as the influencing factors.The relationships among water velocity,vorticity and pressure are discussed when waves interact with breakwater structure,and the three-dimensional analysis of the wave elimination process is carried out.The wave pressure distribution of I-type plate composition breakwater under different submergence depth h,aperture ratio A/Ao,wave height H and wave period T is studied.The temporal characteristics of total wave forces on breakwater structures in horizontal and vertical directions are analyzed.The influence of relative wave height H/d and relative wavelength L/B on the total force of breakwater structure in horizontal and vertical directions is analyzed by dimensionless analysis method.The main conclusions are as follows:When waves interact with breakwater,I-type plate diaphragm destroys water quality point movement,causing water pressure change,resulting in pressure difference,pressure difference affects flow rate,causing water vortex.Pressure,velocity and vortex are related,and the trend of velocity and vorticity is consistent.The larger the velocity,the larger the vorticity.When waves pass through the breakwater,the vorticity is mainly concentrated at the position of I-type plate gap,especially at the bottom of the breakwater,the vorticity below the I-type plate gap is the most concentrated,and there are more vorticity in the wave elimination chamber.The larger the water velocity,the larger the vorticity is.The wave-dissipating mechanism of I-type plate composition breakwater is mainly energy dissipation.The energy dissipation mainly destroys the wave streamlines through the transverse baffles arranged on the breakwater,resulting in turbulence,which then forms positive and negative vortex dissipation wave energy.The turbulent kinetic energy decreases from front to back of breakwater.The wave pressure of breakwater decreases from the front of breakwater to the back of breakwater,and the water backflow phenomenon will occur at the back of breakwater,and the wave pressure will suddenly rise at the back of breakwater.The time course curve of the breakwater structure subjected to the total horizontal wave force and the total vertical wave force varies periodically,and the phase difference exists between the total horizontal wave force and the maximum vertical wave force of the breakwater structure.The total wave force acting on breakwater structure is mainly vertical downward wave force.