Assessment of Dynamic Pressures at Vertical and Perforated Breakwaters through Diffusive SPH Schemes

This paper deals with the development of a 2D weakly compressible SPH model to simulate wave pressures acting on vertical and slotted coastal structures. Attention is devoted to investigate the diffusive term in the continuity equation in order to smooth out the high-frequency numerical noise in the pressure field. A hybrid formulation based on two literature diffusive models is proposed. The interaction between regular waves with vertical and perforated breakwaters is analyzed in time, space, and frequency domain. Numerical results are compared with laboratory experiments and other diffusive SPH formulations, varying the magnitude of the adopted diffusive term. On the basis of an error analysis, the results show that the hybrid formulation gives a better agreement with the experimental data for the majority of the investigated cases. Moreover, SPH simulations highlight nonlinear trends of dynamic pressures in correspondence with geometrical singularities, such as the holes of slotted walls, due to strong pressure drops induced by the flow motion.