CFD/DEM coupled approach for the stability of caisson-type breakwater subjected to violent wave impact. (1st March 2021)

• Record Type: Journal Article
• Authors: Ding, Dong; Ouahsine, Abdellatif; Xiao, Weixuan; Du, Peng
• Is Part Of: Ocean engineering. Volume 223(2021)
• Publication Date: 2021-03-01
• Subjects: Breakwater stability -- Violent wave impacts -- Fluid-porous model -- CFD/DEM coupling; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2021.108651
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: Wave impacts on vertical caissons may cause breakwaters failures. This paper focuses on the analysis of the stability of breakwaters under violent wave impacts by using a triple-coupled Fluid-Porous-Solid model. The fluid model is described by the Volume-Averaged Reynolds-Averaged Navier-Stokes equations in which the nonlinear Forchheimer equations for the porous medium are added to the inertia terms. The solid model, based on the DDA method which is an implicit DEM method, has been used to analyze the movement and the stability of the caisson and armour units by taking into account the shapes of the armor units, as well as the contact between blocks. The developed model has been used for multiple purposes. Firstly, to estimate the variation of the maximum height of the impacting wave with the breakwater slope. A new formula has then been established for this purpose. Secondly, to analyze the influence of the porosity and of the thickness of the porous layer on the Turbulence Kinetic Energy (TKE) distribution around the breakwater structure. The results show that the higher the thickness, the lower the TKE intensity will be. Finally, the model has been used to analyze the stability of shaped armour units placed behind the caisson. Highlights: A coupled Fluid-Porous-Solid model is used to study the stability of breakwater. The porous nonlinear equations are added to the inertia terms of RANS fluid equations. The solid model is based on the Discontinuous Deformation Analysis method. The breakwater stability depends on the thickness and slopes of the porous layer. The stability depends on the shape of armour units and of the cohesion between units.