Effects of sizes and shapes of gravel particles on sediment transports and bed variations in a numerical movable-bed channel

• Published in: Advances in water resources 2014-10, Vol.72, p.84-96
• Main Authors: Fukuoka, S., Fukuda, T., Uchida, T.
• Format: Article
• Language: English
• Subjects: Channel-bed configuration; Channels; Computational fluid dynamics; Computer simulation; Contact; Earth sciences; Earth, ocean, space; Exact sciences and technology; Gravel; Gravel shape; Hydrodynamic force; Hydrology; Hydrology. Hydrogeology; Marine and continental quaternary; Mathematical models; Numerical movable-bed channel; Sediment transport; Settling; Surficial geology; Three-dimensional computation; Water resources
• ISSN: 0309-1708; 1872-9657
• DOI: 10.1016/j.advwatres.2014.05.013

•A numerical movable-bed channel with particles of various shapes was developed.•Numerical movable-bed experiments were conducted for spheres and gravel particles.•Effects of sizes and shapes of particles on sediment transport were investigated.•Engagement effects of gravel particles affect gravel transport rate.•A particle sorting mechanism at the gravel bed was investigated. The paper presents a numerical movable-bed channel capable of simulating three-dimensional motions of flows and gravel particles in different shapes. At first, the numerical channel was tested against results of fixed-bed channel experiments in which gravel particles were transported. Simulated particle motions were validated in comparison with those in the laboratory experiment. Next, numerical movable-bed experiments with sphere particles and gravel particles were conducted. The results of these experiments clearly elucidated the difference in motion between the large and the small particles, effects of shapes of gravel particles on sediment-transport rates, and hydrodynamic forces and contact forces at incipient motion and at settling.