Effects of bedload transport in the vertical profile of the longitudinal mean velocity in hydraulically rough mobile beds

The empirical characterisation of the longitudinal flow velocity and of flow resistance in rough channels hasbecome a classical theme in open-channel hydrodynamics. An analysis of the current theoretical paradigm(schlichting-gersten-2000) shows that there are still open topics of research, despite decades of research. Of particular interest for the characterisation of flow resistance is the definition of the friction velocity, the parametrisationof the roughness height, z0, for a given definition of u* and the universality of the Von Kármán (k). Considerableresearch efforts have also been placed to account for the influence of sediment transport. However, such researchimported the ambiguities of the immobile bed conceptual framework. In this work, key concepts of this frameworkwill be reviewed to accommodate the specificity of open-channel flows carrying bedlaod. The focus will be placedon the Von Kármán constant, k, and the roughness height z0.