Application of Open Boundaries Within a Two-Way Coupled SPH Model to Simulate Non-Linear Wave-Structure Interactions

Abstract

A two-way coupling between the fully non-linear potential flow (FNPF) solver OceanWave3D and the Smoothed Particle Hydrodynamics (SPH) solver DualSPHysics is presented. At the coupling interfaces within the SPH domain, an open boundary formulation is applied. An inlet and outlet zone are filled with bu er particles. At the inlet, horizontal orbital velocities and surface elevations calculated with OceanWave3D are imposed on the bu er particles. At the outlet, horizontal orbital velocities are imposed, but the surface elevation is extrapolated from the fluid domain. Velocity corrections are applied to avoid unwanted reflections in the fluid domain. The SPH surface elevation can be coupled back to OceanWave3D, where the original solution is overwritten. The coupling methodology is validated using a 2-D test case of a floating box. Additionally, a 3-D proof of concept is shown where overtopping waves are acting on a heaving cylinder. The 2-way coupled model proofs to be capable of simulating wave propagation and wave-structure interaction problems with an acceptable accuracy with RMSE values remaining below the smoothing length h.

Fluid initialization and dynamic window for smoothed-particle hydrodynamics simulation

“…Currently, open boundaries in Lagrangian simulations have mainly been used to couple the particle-based simulation with other models. Research works with that objective mainly use the buffer-based approach 10,11 or more rarely Chiron et al’s approach. 12 All these works proposed open boundaries for a static area but do not explore the possibility of moving an area of interest in a larger simulated space which is our goal.…”

SPH Simulations of Real Sea Waves Impacting a Large-Scale Structure

“…One option to achieve wave generation in SPH would see the employment of a moving boundary that mimics the displacement of a wavemaker in experimental wave tanks. This approach has been used extensively in the literature [34,[44][45][46]. Although the generation of waves with a wavemaker-like moving boundary is robust and often accurate, a computational domain size of at least 3 to 4 wavelengths is needed to accurately resolve the physics [47].…”

“…This novel approach has first been introduced in DualSPHysics in [29] and has proven successful in reducing the computational domain size down to only one wavelength. The interested reader can find detailed information on the SPH inlet/outlet algorithm in [42] and its application to wave generation in [29,46].…”