Numerical Simulation Study On The Interaction Of Solitary Wave And Porous Medium Seawall Based On OpenFOAM

Extreme weather events such as tsunami have frequently occurred,causing serious losses to people's lives and property of buildings in coastal areas.The resistance effect of the offshore seawall structure on the wave water body can effectively reduce the wave energy and prevent the invasion of the outer wave to the covered sea area.Vertical porous structure,as an effective substitute for traditional breakwaters,can effectively reduce the impact of waves on coastal and offshore buildings,and is more and more popular in protecting fishing ports,wharfs and controlling coastal erosion near estuaries or lakes.Thus,it is of great practical significance and engineering application value to research the wave dissipation mechanism and structural load of offshore porous seawall under tsunami wave action,and provide a theoretical basis for the protection of offshore building foundation and Coastal Disaster Prevention and mitigation.This paper firstly establishes a three-dimensional hydrodynamic numerical model for the interaction between solitary waves and near-shore porous media seawalls based on the IHFOAM solver in the OpenFOAM open source package,and the accuracy and reliability of the model are validated by using physical experimental data.Results show that the numerical model established in this paper can better capture the hydrodynamic changes during the interaction between solitary waves and near-shore porous seawalls.Then,considering the influence of wave height,water depth,porosity,top height,seawall location and beach slope,the variation of reflection,transmission and wave height reduction eoefficient is discussed according to the wave dissipation characteristics of seawall.The response mechanism of maximum wave force,pore water pressure,overtopping pressure and shock coefficient is discussed according to the wave load on seawall.Finally,based on the above research results,empirical formulas of wave height reduction coefficient and shock force coefficient of porous seawall under solitary wave are proposed.For the wave-breaking characteristics and structural loads of porous seawall under the influence of single factor,under the condition of high wavelet,with the increase of wave steepness,relative position,relative levee height and bank slope,the effect of seawall wave elimination is increased,wave load is increased,and it is weakened with the relative submerged water depth and porosity.In the case of large wave height,the wave-eliminating effect and wave load increase with the increase of relative submerged water depth and porosity,and then decrease with the increase of relative position,relative bank height and bank slope.In addition,when the single influencing factors are certain,the porous seawall has better wave-eliminating effect,and the wave load it receives is significantly smaller than that of the non-porous seawall.The research reveals that the porous seawall can more effectively reduce the stability of the wave impact maintenance structure and provide certain technical support for practical applications.