Flocculation Dynamics of Cohesive Sediment in Turbulent Flows Using CFD-DEM Approach

Abstract

Two-phase computational fluid dynamics - discrete element method (CFD-DEM) framework has gained attention in cohesive sediment transport due to its capability of resolving particle-particle interactions and capturing the time evolution of individual flocs and hence the flocculation dynamics of cohesive sediment in turbulent flows. For cohesive sediments of size smaller than the Kolmogorov length scale, the point-particle approach is commonly used, in which the flow around particles is not fully resolved, and the hydrodynamic force on particles is parameterized by the drag law. The accuracy of floc dynamics, aggregation, breakup, and reshaping therefore strongly depends on force parameterization of individual point-particles that make up the floc. In this chapter, we review recent advances in the state-of-art two-phase CFD-DEM model approach on cohesive sediment transport and make recommendation for future research.