Abstract
A mathematical model is developed on the basis of the equation system of two-phase flow of the conservation of mass and momentum for the fluid and sediment interaction. In the model, the total flow region is divided into three layers composed of the bed load, buffer and suspended load regions over a movable bed. The buffer region has the function of the transition from the bed load motion to the suspension. The interaction between the fluid and sediment, as well as the interaction of sediment particle moving is described on each region. An analysis is done to derive the thickness, the sediment concentration and the velocity of the fluid in each region and the shear stress acting the boundary between each layer. As the results, the distributions of the concentration and the velocity can be predicted for the total flow region. Both distributions obtained from the developed model agrees with the data measured by Vanoni-Nomicos in the movable bed experiments.
