Eulerian Deposition Model for Sediment Mixture in Gravel-Bed Rivers with Broad Particle Size Distributions

Predicting sediment transport and river morphodynamics is a challenging task in gravel-bed rivers where sediment mixtures have various particle sizes. In this study, we derive a binary packing formula by introducing the available porosity for finer sediment particles. The binary packing problem using natural fluvial sediment with various diameter ratios could be reproduced using the proposed formula. We apply this new model to a scenario with mixed-size sediments to calculate gravel-bed porosity. To validate the model, we compare model results to those obtained via an experiment using natural fluvial sediments. The present model exhibits good agreement with the measurements of the deposited sediment in gravel-bed rivers. Because the present model simulates the deposition process of sediment mixtures, it can be coupled with computational fluid dynamic and sediment transport models for predicting morphodynamics in gravel-bed rivers.