Numerical and Experimental Modeling of Regular Wave Interacting with Composite Breakwater

Abstract

Numerical modeling of the interaction between waves and coastal structures is a challenge due to the many nonlinear phenomena involved, such as wave propagation, wave transformation with water depth, interaction between incident and reflected waves, runup/rundown and wave overtopping. For simulating such complex free-surface flows, numerical models based on Lagrangian formulation, such as Smoothed Particle Hydrodynamics (SPH), are on option. Even though validation of these numerical models is essential, comparing numerical results with experimental data is not an easy task. In the present paper, an SPH numerical model is validated comparing numerical results of waves interacting with a composite breakwater with data obtained from physical model tests carried out in one of the LNEC’s flumes. To achieve this validation, the experimental setup was determined to be compatible with the characteristics and capabilities of the numerical model. Therefore, the flume dimensions are exactly the same for both the numerical and physical model and conditions of wave generation are identical, which allows determining the accuracy of the numerical model, particularly regarding complex phenomena such as wave propagation, wave-breaking and impact loads on the vertical front of the composite breakwater. The numerical results agree well with the physical model tests. The free-surface level is well estimated, with a concordance index between 90% and 97%. Pressure at the vertical wall shows impact loads with high intensity and short duration with a concordance index between numerical and experimental of about 80%.