Sediment transport may occur during fast geomorphic transients as a consequence of strong upward momentum fluxes due to turbulence and/or of intense erosion of a loose bed. Under these circumstances, sediments will move with the distinctive features of bed-load in the region close to the bottom, whereas suspended sediment will follow the carrying fluid in the upper region of the flow. The paper presents a two-phase model able to describe both bed and suspended loads. While bed-load dynamics is modeled con-sidering the particle-bottom and particle-particle collisions and drag received by the fluid, the suspended one is considered just advected by carrying flow. The model is applied to analyzed the dam-break waves over erodible beds of light sediment. The numerical results reproduce the main features of the experiment, putting in evidence the different dynamics of bed and suspended loads.
Two-phase modelling of total sediment load in fast geomorphic transients
LEOPARDI, Angelo;
2012-01-01
Abstract
Sediment transport may occur during fast geomorphic transients as a consequence of strong upward momentum fluxes due to turbulence and/or of intense erosion of a loose bed. Under these circumstances, sediments will move with the distinctive features of bed-load in the region close to the bottom, whereas suspended sediment will follow the carrying fluid in the upper region of the flow. The paper presents a two-phase model able to describe both bed and suspended loads. While bed-load dynamics is modeled con-sidering the particle-bottom and particle-particle collisions and drag received by the fluid, the suspended one is considered just advected by carrying flow. The model is applied to analyzed the dam-break waves over erodible beds of light sediment. The numerical results reproduce the main features of the experiment, putting in evidence the different dynamics of bed and suspended loads.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
