IAHR, founded in 1935, is a worldwide independent member-based organisation of engineers and water specialists working in fields related to the hydro-environmental sciences and their practical application. Activities range from river and maritime hydraulics to water resources development and eco-hydraulics, through to ice engineering, hydroinformatics, and hydraulic machinery.
Log On
About IAHRDirectoryCommitteesMy IAHRNews & JournalseLibraryeShopEventsJoin IAHRWorld CongressDonate
spacer.gif
spacer.gif eLibrary
spacer.gif eLibrary
You are here : eLibrary : IAHR World Congress Proceedings : 32nd Congress - Venice (2007) : THEME A: Engineering and Management of Fresh-water Systems : Limit rolling entrainment condition of sedimentbed particles at high slopes
Limit rolling entrainment condition of sedimentbed particles at high slopes
Author : Pigozzi Diego , Gregoretti Carlo , Pontin Marco
A model is presented to determine the initiation of the entrainment of bed particles in an unidirectional steady-uniform stream flow. The model concerns the analyses of equilibrium of a spherical particle resting on three closely and equal spherical particles of different radius and subject to the gravity, hydrodynamic, buoyancy and seepage forces. The analysis of the equilibrium is carried out by the virtual works principle undergoing the uppersphere to a rotation, without sliding, about an axis selected as the mean between two possible extreme ones to take in account the chaotic position of particles respect to the flow direction. The relative degree of exposure of a particle to the stream flow is introduced. A velocity distribution of low submergence flow is used and the theoretical depths predicted by the model are compared with the ones from previous experimental tests on the entrainment of sediment at high slopes with satisfactory results.
File Size : 420,093 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 32nd Congress - Venice (2007)
Article : THEME A: Engineering and Management of Fresh-water Systems
Date Published : 01/07/2007
Download Now