Author(s): Afroja Parvin; Julian Koellermeier; Giovanni Samaey
Linked Author(s):
Keywords: Shallow water Exner moment model; Bedload and suspended load; Hyperbolicity; Dam-break; Wet-dry front
Abstract: Sediments entrained in a flow can be transported along the riverbed as bedload, consisting of coarser particles that move by rolling, sliding, and jumping, or they can be transported in suspension as suspended load advected by the flow. Accurately modeling sediment transport in shallow water environments is essential for understanding river dynamics, coastal morphology, and engineering applications. This study focuses on a model based on a vertically resolved shallow flow model coupled to a bedload Exner model and a volumetric concentration equation for the suspended particles. The classical sediment transport model based on shallow water equations describes the transport process using the depth-averaged horizontal velocity along the vertical direction. Contrary to that, the vertically resolved so-called Shallow Water Moment Equations used in this work have the flexibility to recover the vertical structure of the fluid with any velocity profile and include the non-linear friction term depending on the near-bed velocity, which makes it feasible to approximate the velocity close to the sediment layer. The explicit form of the model allows for conducting mathematical analyses such as hyperbolicity proof, equilibrium states, and stability analysis. This study presents several numerical experiments, including dam-break and wet-dry front, and compares the numerically simulated results against experimental data to validate the model.
Year: 2025