SPH modelling in coastal engineering

Alejandro J. C. Crespo, Corrado Altomare, Jose M. Domínguez, Tomohiro Suzuki, Toon Verwaest, Moncho Gómez-Gesteira

Monday 29 june 2015

14:35 - 14:50h at Central America (level 0)

Themes: (T) Special session, (ST) Smoothed particle hydrodynamics and other meshfree methods

Parallel session: 2H. Special session: Smoothed Particle Hydrodynamics and other meshfree methods

The design of coastal defences requires a proper assessment of actions exerted by the sea waves on the structures, such as run-up heights, overtopping flow rates and velocities, wave forces and pressures. The numerical modelling can represent a useful and complementary tool to physical model tests in order to cope with the aforementioned problems of coastal engineering. The Smoothed Particle Hydrodynamics (SPH) method uses particles to represent a fluid and these particles move according to the governing dynamics. When simulating free-surface flows, the Lagrangian nature of SPH allows the domain to be multiply-connected, with no need of a special treatment of the surface, making the technique ideal for studying violent free-surface motion. SPH has been used to describe a variety of free-surface flows (wave propagation over a beach, plunging breakers, impact on structures and dam breaks). The present work aims to demonstrate the accuracy of SPH to quantify the sea wave forces on coastal defences such as storm return walls. First, SPH has been validated using physical model test data in terms of water surface elevation and wave forces showing a very good agreement with relatively short time series of regular waves and random waves are considered. As next step, new developments in the SPH code lead to more accurate results and to the possibility of studying a wider range of coastal engineering applications. These latest developments are: - Wave generation of irregular wave patterns - Passive wave absorption by damping - Active wave absorption that mimics the physical AWAS system - Variable resolution or particle refinement in the areas of interest - Coupling with wave propagation models such as SWASH SPH model can be proposed as complementary tool to physical model experiments for a preliminary design of the coastal defences, within the stated limitations and with considerations of relative uncertainties.