Under the action of marine currents,non-cohesive sediments evolve by bed-load,by saltation or suspension depending on their granulometry.Several authors have considered that the movement of sediment is bidimensional a...Under the action of marine currents,non-cohesive sediments evolve by bed-load,by saltation or suspension depending on their granulometry.Several authors have considered that the movement of sediment is bidimensional and modelized the effects of swell by a constant velocitynear the seabed.Here we have studied the velocity profile of fluctuating currents near the seabed and studied the movement of sediment in 3D.The results show that in the areas of study（surf and swash）the movement of sediment occurs in a volume,and the evolution of sediment varies from an areato another.The obtained theoretical profiles of the position and velocity vectors confirm the observations of several authors.展开更多
The subject of present study is the application of mesh free Lagrangian two-dimensional non-cohesive sediment transport model applied to a two-phase flow over an initially trapezoidal-shaped sediment embankment. The g...The subject of present study is the application of mesh free Lagrangian two-dimensional non-cohesive sediment transport model applied to a two-phase flow over an initially trapezoidal-shaped sediment embankment. The governing equations of the present model are the Navier-Stocks equations solved using Weakly Compressible Smoothed Particle Hydrodynamics （WCSPH） method. To simulate the movement of sediment particles, the model considers a powerful two-part technique; when the sediment phase has rigid behavior, only the force term due to shear stress in the Navier-Stokes equations is used for simulation of sediment particles＇ movement. Otherwise, all the Navier-Stokes force terms are used for transport simulation of sediment particles. In the present model, the interactions between different phases are calculated automatically, even with considerable difference between the density and viscosity of phases. Validation of the model is performed using simulation of available laboratory experiments, and the comparison between computational results and experimental data shows that the model generally predicts well the flow propagation over movable beds, the induced sediment transport and bed changes, and temporal evolution of embankment breaching.展开更多
基金the "Ministère d’Etat Chargé de l’Enseignement Supérieure et de la Recherche Scientifque (MECESRS)" for their support during this work
文摘Under the action of marine currents,non-cohesive sediments evolve by bed-load,by saltation or suspension depending on their granulometry.Several authors have considered that the movement of sediment is bidimensional and modelized the effects of swell by a constant velocitynear the seabed.Here we have studied the velocity profile of fluctuating currents near the seabed and studied the movement of sediment in 3D.The results show that in the areas of study（surf and swash）the movement of sediment occurs in a volume,and the evolution of sediment varies from an areato another.The obtained theoretical profiles of the position and velocity vectors confirm the observations of several authors.
文摘The subject of present study is the application of mesh free Lagrangian two-dimensional non-cohesive sediment transport model applied to a two-phase flow over an initially trapezoidal-shaped sediment embankment. The governing equations of the present model are the Navier-Stocks equations solved using Weakly Compressible Smoothed Particle Hydrodynamics （WCSPH） method. To simulate the movement of sediment particles, the model considers a powerful two-part technique; when the sediment phase has rigid behavior, only the force term due to shear stress in the Navier-Stokes equations is used for simulation of sediment particles＇ movement. Otherwise, all the Navier-Stokes force terms are used for transport simulation of sediment particles. In the present model, the interactions between different phases are calculated automatically, even with considerable difference between the density and viscosity of phases. Validation of the model is performed using simulation of available laboratory experiments, and the comparison between computational results and experimental data shows that the model generally predicts well the flow propagation over movable beds, the induced sediment transport and bed changes, and temporal evolution of embankment breaching.
