Establishment And Application Of Hydrodynamic Numerical Model Of New Permeable Breakwater Based On OpenFOAM

The permeable breakwater can be used in future deep-sea structural protection projects due to its light structure and good water exchange.Appropriate numerical simulation methods are used to evaluate the hydrodynamic characteristics of the permeable levee,which can not be affected by on-site test conditions,can save manpower,material and financial resources,and has various analysis methods,which greatly improves the calculation efficiency.In this paper,based on previous studies in the field of OpenFOAM numerical wave flume and permeable breakwater,the relevant parameters of numerical wave flume are optimized and adjusted,and the numerical empty flume constructed is compared and analyzed from the aspects of grid partition,theoretical verification,active absorption and wave elimination.On this basis,two-dimensional arc plate permeable breakwater and three-dimensional square box comb permeable breakwater are selected as the representative of the application of new permeable breakwater,and corresponding hydrodynamic numerical models are established.The numerical model results of the permeable breakwater are compared with the experimental results of the physical model in corresponding working conditions in terms of wave dissipation,force and flow field.The reliability of the numerical model is verified,and then analyze the hydrodynamic characteristics of the two new type of permeable breakwater.However,the application is not limited to the specific structure form,so it can provide a setting scheme and reference for future research on the hydrodynamic numerical model of a new type of permeable breakwater.The following results are obtained through research and analysis:1.The numerical empty flume is verified by theoretical solution,grid independence and active absorption system.And the wave surface duration curves obtained from the numerical simulation results under different wave periods match well with the results obtained from the physical test flume.The results show that the accuracy of regular wave generation in numerical flume can be effectively improved by appropriate mesh refinement and the addition of damping active absorption system.2.The results of wave dissipation obtained by the two-dimensional hydrodynamic numerical model of the arc plate permeable breakwater are in good agreement with the results of the corresponding physical model tests,the two-dimensional flow field image of the transverse section can reflect the experimental phenomenon more intuitively.3.The wave dissipation results of the three-dimensional hydrodynamic numerical model of the square box comb permeable breakwater and the stress results of each surface of the box body are close to the results of the physical model,and the profile images presented by the numerical simulation of the flow field are in good agreement with the phenomenon at the corresponding position of the test.4.When the relative dike width increases,the transmission coefficient of the arc plate permeable breakwater decreases,while the reflection coefficient increases.The wave pressure on both sides of the arc plate is higher than that in the middle of the arc plate,and the wave impact on the upper surface is greater.The positive and negative horizontal wave forces of the arc plate are symmetrically distributed,and vortices are easy to form on the back wave side of the arc plate,accompanied by water turbulence.5.The transmission coefficient of square box comb permeable breakwater decreases with the increase of relative plate width,but the reflection coefficient is constant between 0.35 and 0.45.The closer the measuring point on the box is to the benchmark surface of the water,the greater the pressure is measured.The horizontal wave force on each loading surface has a great influence on the box body.There will be water convergence on the back wave surface,and the water turbulence effect in the cavity is more obvious.