Hybridization of the Wave Propagation Model SWASH and the Meshfree Particle Method SPH for Real Coastal Applications

Two computational models, Simulating WAve till SHore (SWASH) and DualSPHysics, with different computational costs and capabilities have been hybridized in this work. SWASH is a time-domain wave model based on a finite difference method for simulating nonhydrostatic, free-surface and rotational flow while DualSPHysics is a Lagrangian meshless model based on the Smoothed Particle Hydrodynamics (SPH) technique. SWASH is a reliable model to generate and propagate waves in large domains, whereas DualSPHysics is normally used in areas close to the coastline to provide a detailed description of the interaction between sea waves and coastal structures. The presented technique is a one-way coupling, with a hybridization point where the information from SWASH is passed to DualSPHysics. SWASH is used to propagate waves along the fluid domain and to calculate velocities at different depths at the position of the hybridization point. Waves in DualSPHysics are generated by means of a moving boundary (MB) whose displacement in time is reconstructed using the velocities provided by SWASH. Each particle that forms the MB is displaced with its correspondent velocity that depends on its depth. The hybridization technique is validated with experimental data and the resulting model is proved to reproduce accurately wave heights and orbital velocities. Thus, the hybrid model preserves the flexibility and capabilities of DualSPHysics with important improvements in efficiency. In addition, it simulates wave propagation even more accurately than DualSPHysics taking advantage of SWASH strengths.