Session: 08-02-01 Wave–Structure Interaction, Noise Modeling, and Marine Hydrodynamics

Submission Number: 180574

Efficient Numerical Simulation of Nonlinear Wave Generation via GPU-Accelerated HOS–SPH Coupling 

To accurately evaluate the performance of ships and floating platforms under realistic sea states, it is essential to reproduce short-crested irregular waves with high fidelity in numerical simulations. The High-Order Spectral (HOS) method is widely used for generating nonlinear waves due to its high computational efficiency and accuracy. However, it faces difficulties in handling fluid-structure interactions and wave-breaking phenomena. In contrast, the Smoothed Particle Hydrodynamics (SPH) method has been rapidly developed in recent years and is increasingly applied to simulate nonlinear ship and platform motions under various wave conditions. The first author has previously investigated nonlinear ship motions in regular wave cases and confirmed that SPH results show good agreement with experimental data, particularly for large wave amplitudes.

Nevertheless, generating three-dimensional short-crested irregular waves using pure SPH remains challenging. The large computational domain required involves a tremendous number of particles, leading to extremely high computational cost. Moreover, the wave energy dissipation problem, which is relatively minor in small SPH domains, becomes significant in the large domains necessary for short-crested wave simulations.

To address these issues, this study proposes an HOS-SPH coupling framework that enables both accurate and efficient wave generation. In this approach, inlet/outlet and relaxation zones are implemented in the SPH domain, where the velocity field obtained from HOS is introduced through a spatially varying coupling coefficient depending on particle position. The open-source interface Grid2Grid, originally developed for coupling HOS with the Eulerian CFD solver foamStar, is adopted and further modified. In the original framework, Grid2Grid interpolates the HOS free-surface data onto the Eulerian volumetric computational grid on the CPU. In the present study, it has been extended to interpolate the volumetric velocity field from the HOS grid directly onto Lagrangian SPH particles. Furthermore, to enhance computational efficiency, Grid2Grid has been parallelized on the GPU, allowing all B-Spline interpolation operations to be executed in GPU memory. Since the SPH solver itself also runs entirely on the GPU, particle data are stored and computed directly in GPU memory, minimizing data-transfer overhead.

Several benchmark tests, including two-dimensional regular and irregular waves, as well as three-dimensional short-crested waves, are conducted to validate the developed HOS-SPH coupling model. The results show that the coupled model reproduces two-dimensional wave fields in excellent agreement with experimental and pure HOS results. For three-dimensional cases, the accuracy at high crests and deep troughs remains acceptable, while minor underestimations appear in the smaller wave components. Overall, the proposed GPU-based HOS-SPH coupling scheme demonstrates strong potential for efficiently simulating complex three-dimensional short-crested wave fields.

Presenting Author: Chong Ma National Maritime Research Institute, Japan

Presenting Author Biography: The presenting author is a senior researcher at the National Maritime Research Institute (NMRI), Japan. His main research interests include nonlinear hydroelasticity, SPH–FEM and SPH–HOS coupling, LNG tank sloshing, and the development of ship structural monitoring systems.

Authors:

Chong Ma National Maritime Research Institute, Japan
Benjamin Bouscasse Nantes Université, École Centrale Nantes, CNRS, LHEEA, UMR 6598, Nantes, France
Guillaume Ducrozet Nantes Université, École Centrale Nantes, CNRS, LHEEA, UMR 6598, Nantes, France