The processes of sediment transport in high flow intensity are studied through numerical simulation using a coupled CFD (computational fluid dynamics)-DPM (discrete particle method) model with a focus on discussing the co-existence problem of bed load and suspended load and the corresponding sediment concentration distribution. It is shown that for the sediment-laden flows, the components of turbulence intensity decrease slightly as sediment concentration increases. The bed load and suspended load both coexist in a transition layer. Particle collision plays an important effect on the velocity of bed load movement. The total sediment transport rate obviously increases with the increase of flow intensity, but the bed load transport rate does not clearly increase. In the present study, the maximum value of suspended sediment concentration curve is about 7%, and increases with the increase of the flow intensity. The simulation results are generally consistent with experimental observation.

使用耦合CFD（计算流体动力学）-DPM（离散粒子法）模型通过数值模拟研究高流强度下的泥沙输运过程，重点讨论床载和悬浮载荷的共存问题以及相应的泥沙浓度分布。结果表明，对于含沙流，湍流强度分量随着含沙量的增加而略有下降。河床荷载和悬吊荷载共存于一个过渡层。粒子碰撞对床载运动的速度有重要影响。总泥沙输运率随着流强的增加明显增加，但床载输运率没有明显增加。在目前的研究中，悬浮泥沙浓度曲线的最大值约为7%，并随着流动强度的增加而增加。模拟结果与实验观察基本一致。