SPH Modelling Of Wave Overtopping On Sloping Breakwater

An 2D active absorbing wave flume was built based on the corrected SPH method by CSPM and Reimann solver to study the water dynamics of wave run-up and overtopping on sloping breakwaters.Firstly, the research of wave overtopping on breakwaters and the applications of SPH in hydrodynamics were briefly reviewed.Secondly, the basic equations, namely function approximation and particles approximation, were introduced in detail. The relative implementation technologies of SPH, such as boundary conditions, particles search algorithm and time integral, were also discussed. and then, the change of free surfaces profiles at different points when solitary wave run-up and overtopping on impermeable sloping breakwater were studied to validate the numerical models used in this paper by comparing SPH results and experiment data.Finally, regular wave run-up and overtopping on permeable sloping breakwaters were studied. The slope was dealt as porous media, namely, the permeable layer under the water surface was filled with particles. The spatial average flow was solved. The SPH model solves NS equations for the flows outside the porous media and the NS type equations for the flows inside the porous media. The presence of porous media is considered by including additional friction into the equations. Water surface elevations at different points and pressure fields in the porous media were both studied. And then the relations between overtopping mass and different periods, different wave heights, different gradient and diameters were studied. The results show that:the wave surfaces predicted by the model based corrected SPH is in good agreement with experiment data; in the range of numerical model, overtopping mass changed greatly with wave periods, wave height and gradient. the overtopping mass increases when wave height and period increase and decreases when gradient increases; porosity has least influence on overtopping mass, the overtopping mass has a least value when porosity is 0.4 in small period, but the difference is minor, when the period is 2 second, overtopping mass was no change with porosity anymore; when the size of diameter increases from 10mm to 25mm, overtopping mass decreases evidently, when the size of the diameter is greater than 25mm, overtopping mass changes little.