Reza Barati - Ph.D. candidate, Faculty of Civil and Environmental Engineering, Tarbiat Modares University, Tehran, Iran.
Seyed Ali Akbar Salehi Neyshabouri - Prof., Water Engineering Research Center, Department of civil Engineering, Tarbiat Modares University, Tehran, Iran
Goodarz Ahmadi - Prof., Department of Mechanical and Aeronautical Engineering, Clarkson University,Potsdam, New York, USA

Saltation is the dominant mode of the sediment transport in rivers. The focus of the present study is on the development of an accurate particle saltation model for the range of sand to gravel in the Lagrangian approach. The model includes the non-linear drag force, the shear lift force, Magnus force, the buoyancy force, the added mass force, the Basset history force and torque. A sub-model for the random process of the particle impact and rebound from the channel bed is also included (i.e. particle–bed collision or splash model). The results of the developed model were validated against experimental data. By using the developed model, the mechanism of particle–bed collision was investigated under rough and smooth bed conditions. The results showed that sediment saltations are quickly disappear under horizontal smooth bed surface. Therefore, the consideration of a bed roughness model is essential for the simulation of the continuous bed-load saltation process

Lagrangian model, non-cohesive sediment, Successive saltation, particle–bed collision,rough and smooth bed