A 2D numerical model for simulation of cohesive sediment transport

The study of the characteristics of fine-grained and cohesive sediments due to its filling characteristics in harbors and ports is an important subject in coastal studies. Fine-grained cohesive sediments have special complicated characteristics as compared to other sediments regarding their behavior. Hence, numerous research works have been carried out to establish well validated physical and mathematical descriptions of the behavior and outcome of concentrated near-bed cohesive sediment suspensions and their interaction with the water column and the bed as well as the turbulence characteristics of sediment laden flow. A two-dimensional model is developed in this study that includes: a cohesive sediment simulator module, processes such as advection and diffusion of cohesive sediment, flocculation and its effect on the settling velocity of cohesive sediment particles, consolidation of bed layers and sediment transport between layers, substrate shear stress variations affecting the simultaneous presence of wave and flow, bed morphology, deposition and erosion. In all these processes, the depth is considered according to the actual topography of the bed. For verification of model performance the model results have been compared with the MIKE 21 model results against the field data reported during the construction phase and at the simulation stage of Ho Bay, a case study presented by DHI (MIKE, 15). The comparisons indicate a favorable accuracy of the present model performance in simulation of cohesive sediment transport.