Saturated, collisional flows of spheres over an inclined, erodible bed between vertical sidewalls

• Published in: Advances in water resources Vol. 72; pp. 15 - 21
• Main Authors: Larcher, Michele, Jenkins, James T.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier Ltd 01.10.2014; Elsevier
• Subjects: Approximation; Debris flow; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; Exact solutions; Fluid dynamics; Grains; Granular systems; Hydrology; Hydrology. Hydrogeology; Inclination; Kinetic theory; Mathematical analysis; Mixture theory; Natural hazards: prediction, damages, etc; Slopes; Water resources; Mixture theory; Debris flow; Kinetic theory; Granular systems; debris flows; energy balance; concentration; grains; surface water; viscosity; depth; water resources; prediction; granular materials; kinetics; flow; theory; energy
• ISSN: 0309-1708; 1872-9657
• DOI: 10.1016/j.advwatres.2014.03.002

•We use an extension of kinetic theory for dense flows.•We study inclined particles–fluid flows over a mobile bed.•We predict the range of slopes for which fully saturated flows are possible.•We predict how the granular concentration varies as a function of the slope.•We obtain analytical expressions for the depth of flow and for the volume flow rate. We consider a steady, uniform, dense, fully-saturated, gravity-driven, inclined flow of water and identical spherical grains over an erodible bed between parallel, vertical sidewalls. The grains are inelastic and the energy lost in their interaction is also influenced by the fluid viscosity. We use an extension of kinetic theory for dense flows and employ approximate integrations of the momentum and energy balances for the grains in order to obtain analytical expressions for the depth of flow and for the volume flow rate of the mixture as functions of inclination and average concentration. We also predict the range of slopes for which dense, fully-saturated flows are possible. The predictions are in reasonable agreement with already published experimental results.