Numerical Simulation Of Pile-foundation Penetrated Breakwater Based On OpenFOAM

At present,with the continuous development of Marine science and technology,maritime trade between countries is increasing,which is of great urgency for the construction of ports.China is vigorously developing maritime economy and trade.In recent years,with the increasing awareness of environmental protection,the country has begun to strengthen measures to regulate Marine buildings.Build green environmental protection breakwater is the current first choice,according to the national policy provisions of the traditional impervious breakwater can not be built,so permeable breakwater future vigorously develop one of the forms of breakwater.Compared to traditional vertical breakwater in the Marine environment governance baffle type void,pile dike has obvious superiority characteristic,the structure of the bottom can flow water bodies,make the breakwater seawall external and internal water free flow,the upper part of the structure can prevent the occurrence of the waves,openwork breakwater of development will be the main trend of building.This paper mainly uses Open FAOM to establish a numerical flume,numerically simulate the hydrodynamic characteristics of different forms of baffle permeable breakwater,study its wave elimination mechanism and optimize the form of permeable breakwater,which has reference value for engineering application.Firstly,OpenFOAM software,numerical simulation control equation,boundary conditions,finite volume method equation discretization,PISO algorithm,dynamic mesh solution,wave generation method and wave removal method are introduced.The numerical wave flume is established.The accuracy of the numerical wave flume is verified by physical model test and micro wave theory.Secondly,the influences of the permeable breakwater with single vertical baffle,double vertical baffle and three vertical baffle on the transmission and reflection coefficients under different working conditions of regular waves are investigated.The results show that the transmission coefficient of the three-story vertical wave baffle is the smallest when compared with that of the single-story vertical wave baffle,the two-story vertical wave baffle and the three-story vertical wave baffle.The transmission coefficient of single-layer vertical wave baffle is the largest,which is 0.7.Double vertical transmission coefficient of wave plate in the middle of the both,the reflection coefficient is the result,in contrast,single minimum vertical reflection coefficient of wave plate structure,three layers of wave plate vertical reflection coefficient is the largest,double vertical wave reflection coefficient in the middle of the two,three the position of the wave plate structure in the middle layer of the vertical baffle on the structure of transmission coefficient and the reflection coefficient is affected,comprehensive consideration,The two-layer vertical baffle permeable breakwater and three-layer vertical baffle permeable breakwater are better in engineering.After that,a systematic numerical simulation study was carried out on the hydrodynamic characteristics of the forward-inclined and then vertical double-baffle pile permeable dike.The results show that: Compared with the traditional vertical baffle,the transmission coefficient of the inclined plate is smaller than that of the traditional vertical baffle.Compared with the transmission coefficient of the two,the maximum reduction is 38%.With the increase of the inclined Angle,the larger vortex is generated at the bottom of the inclined plate,which leads to the increase of the dissipation coefficient of the inclined plate,which is beneficial to improve the performance of the plate breakwater.When the tilting Angle of the front baffle of the permeable dike reaches 40°,the transmission coefficient of the structure is basically stable.With the increase of the tilting Angle of the front baffle,the transmitted wave energy and reflected wave energy decrease,while the dissipated wave energy increases.The wave climbing height changes little,and the wave retaining effect is good.It can be seen that the inclined baffle structure is superior to the vertical baffle structure.Finally wave structure of box type void,wave properties of embankment to carry out the numerical simulation research,the research results show that compared with traditional vertical plate wave structure,box-type structure with smaller transmission coefficient,minimum transmission coefficient is 0.15,larger reflection coefficient,analysis of dissipation caused by viscous flow,vertical plate wave structure is mainly composed of shock wave dissipation,The box type wave retaining structure is mainly dissipated by the vertical movement of the water quality point restrained by the flat plate.The analysis of the flow field diagram shows that when the wave passes through the box type wave retaining structure,most of the waves are reflected,while the few transmitted waves are restrained by the horizontal bottom plate,and the wave height decreases and tends to be stable,so as to achieve better wave elimination effect.