Study of sediment transport under saltation regime in rough bed: Bed-load grain diffusion

Reza Barati, Seyed Ali Akbar Salehi Neyshabouri, Goodarz Ahmadi

Tuesday 30 june 2015

13:03 - 13:06h at Mississippi (level 1)

Themes: (T) Sediment management and morphodynamics, (ST) Sediment transport mechanisms and modelling, Poster pitches

Parallel session: Poster pitches: 5A. Sediment - Erosion

Saltation is the dominant mode of the sediment transport in rivers. Bedload Grain diffusion refers to the scattering of sediment grains while moving close to the bed. The purpose of the present study is to investigate sediment grains diffusion with different scale ranges in open channel flow. A 3D Eulerian-Lagrangian theoretical/numerical model was developed which can be used for the successive saltation of the group of sediment grains using Discrete Element Method (DEM). Different hydrodynamic forces were included in the model. The turbulence effect is also incorporated. The non-cohesive sediments grains for the range of sand to gravel were considered. The verification of the model indicated that the proposed terms for the hydrodynamic forces in the model can accurately described the trajectory of the particles. The results shown that inter-particle collisions as well as particle–bed collision introduce transverse diffusion.