Coupling SPH boundary conditions for dam-break cases in the presence of abrupt bottom variations

The present work deals with a Smoothed Particle Hydrodynamics (SPH) model to simulate 2D unsteady flows generated by water tank collapse in the presence of trapezoidal obstacles, adopting coupled solid boundary conditions (BC). In SPH context the modelling of BC represents a relevant topic for fluid-dynamics problems. The first attempt to deal with solid bodies was referred to boundary particles exerting forces on the fluid. Another approach to enforce BC is characterized by the use of ghost particles that reproduce part of the computational fluid domain, which is close to the boundary at hand, symmetrically in a thin layer. In any case the application of a only mentioned BC shows some limitations to prevent the water leakage outside the solid boundaries during strong impacts. The presence of shallow water conditions also requires to model the bottom roughness. Here the two BC approaches are coupled to simulate complex 2D dam-break phenomena. Moreover the calibration of the involved parameters to model the flow and the external roughness at the boundaries is performed. The comparisons between numerical and experimental results show the SPH capabilities in simulating water levels subjected to sharp changes due to the occurrence of splash and bore phenomena.