ABSTRACT
The riverbanks are composed of porous materials, whose erosion by ship-generated waves is a problem on navigable reaches of rivers. Inside the porous structure, the energy of waves is dissipated by the flow friction. When this internal flow is intense, the risk of erosion of riverbanks appears. In order to know the stability of riverbanks, the flow motion and the pressure distribution around and inside these porous structures must be determined. Modeling the wave interaction is challenging due to the need to know the precise fluid pressure distribution depending on the porosity of the material. The mesh-free Smoothed Particle Hydrodynamics (SPH) method is developed to model a fluid-porous media interaction where the wash waves generated by ships interact with the riverbanks. Improvements of SPH methods were proposed to correct the problems concerning the pressure fields and boundary conditions. The Incompressible SPH (ISPH) methods introduce a singularity on the interface between the pure fluid zone and the porous medium because of the different particle size in each zone. For correcting the problem, two methods for the treatment of the interface boundary between the pure fluid and porous medium are proposed: a transition zone with a gradually variation of the particles size in function of the porosity and an approximation of the pressure using a 2nd order Taylor expansion of the smoothing function.
