Simulation of caisson breakwater movement using 2-D SPH

Smoothed Particle Hydrodynamics (SPH) is used to simulate the movement of a caisson breakwater in the surf zone. The open-source code SPHysics is used with a Riemann solver-based formulation. The friction force between the moving caisson and the bed is modelled with a transition from static to dynamic friction force. Results are presented for two-dimensional simulations and compared with experiments for the movement of a caisson breakwater under the forcing of periodic waves. Promising agreement with experimental data is obtained for the displacement and the horizontal forces on the caisson. It is demonstrated that the peak impact forces are better captured using finer resolution and that a Riemann solver-based formulation produces a better agreement with experiment for the predicted caisson displacement than conventional SPH.