Modelling of sediment transport and bed deformation in rivers with continuous bends

- We improve a 2D RNG k-ε sediment model including the effect of secondary currents.
- We develop an efficient semi-coupled scheme to solve sediment models numerically.
- Bed deformation induced by transport of non-uniform suspended and non-uniform bedload sediments is investigated.
- The variation of effective bed material granularity has been examined.

A two dimensional (2D) RNG k-ε sediment model including the effects of secondary currents is developed to simulate the sediment transport and bed deformation in rivers with continuous bends. Non-uniform suspended and bedload sediment transports and the variation of effective bed material size distribution are included in the model. A semi-coupled scheme for sediment model is proposed, which can be used for simulating both the long- and short term sediment transport whenever riverbed changes. The model is applied to simulate the flow and sediment transport in the upper reach of the Yellow River which is a typical natural river reach with continuous bends. The river bed deformations caused by suspended and bedload sediments are investigated. Good agreement between the numerically simulated results and the field measurements is obtained, indicating that the model is capable of simulating the sediment transport and predicting the bed deformation of rivers having continuous bends with reasonable accuracy.