Improved relaxation zone method in SPH-based model for coastal engineering applications. (December 2018)

• Record Type: Journal Article
• Authors: Altomare, C.; Tagliafierro, B.; Dominguez, J.M.; Suzuki, T.; Viccione, G.
• Is Part Of: Applied ocean research. Volume 81(2018)
• Page Start: 15
• Page End: 33
• Publication Date: 2018-12
• Subjects: Smoothed Particle Hydrodynamics -- Relaxation Zone -- Coupling algorithm -- Wave generation and absorption -- SWASH -- Wave-Structure interaction; Ocean engineering -- Periodicals; 620.416205
• DOI: 10.1016/j.apor.2018.09.013
• Languages: English
• ISSNs: 0141-1187

Abstract

Graphical abstract: Highlights: An improved algorithm for wave generation and absorption for meshless Lagrangian methods is proposed. The algorithms, based on the Relaxation Zone method (RZ), can be extended to model coupling. A detailed validation using Smoothed Particle Hydrodynamics and NLSW solvers is provided. A detail methodology to design the setup of RZ in SPH is proposed and optimized for wave generation and abortion. The results prove that the RZ method is convenient from the point of view of both accuracy and computing time. Abstract: An improved Relaxation Zone (RZ) method has been implemented in the meshless SPH-based DualSPHysics model. Final purpose of this work is to have a general wave generation scheme that allows coupling SPH-based models to other models, e.g. Eulerian based wave models, besides employing the RZ as alternative wave generation in SPH as a stand-alone scheme. Using RZ in SPH, the movement of the fluid particles is controlled by correcting their orbital velocity by means of a weighting function in a specified generation area. In the present work, the new technique is used to couple DualSPHysics to the non-hydrostatic wave-flow model SWASH. The results of RZ employed both as stand-alone wave generation technique and as coupling framework with SWASH model are validated for wave generation and wave reflection for monochromatic waves. Then, the method is tested successfully for generation and absorption of irregular waves. Finally, the coupling between DualSPHysics and SWASH using RZ is validated against experimental data concerning the wave flow impacts on vertical walls. A procedure for a proper design of the RZ (i.e. shape of the weighting function, size of the RZ) is described in the present work. Overall, the results indicate that the proposed improved RZ technique is among the most effective alternatives for wave generation in SPH-based models for coastal engineering application.