Abstract
Dynamics of river bedforms which is an interfacial instability phenomenon between turbulent open channel flow and movable bed significantly affect the flow structures and sediment transport dynamics in rivers, so that this have been an classical and important research topic in the field of river engineering. Here, we perform a linear stability analysis for several combinations of flow and sediment transport submodels, specifically, a shallow flow model and a Boussinesq type depth-integrate model for hydrodynamic model, and an equilibrium and a non-equilibrium bedload transport model for sediment mass conservation model. We then investigate how the submodels adopted determine the linear stability and the wavelength of river bedforms. The results show that the combination of the Boussinesq model and the non-equilibrium bedload transport model can explain the antidune instability and its finite wavelength observed in several published experiments, whereas, use of each submodel alone is insufficient to explain the finite wavelength of antidunes.
