A Relationship between Friction Factor and Energy Slope at Incipient Motion of Sediment Particles

作者: A. Ramakrishna Rao

DOI: 10.1007/978-3-662-11300-4_28

关键词: GeologyShieldsFlow (psychology)Free surfaceGeotechnical engineeringSedimentIntensity (heat transfer)Critical resolved shear stressCritical ionization velocityMechanicsPlane (geometry)

摘要: As the flow intensity increases on a particular stationary and plane sediment bed, condition is eventually reached at which bed particles are unable to resist hydrodynamic forces thus initial movement of occurs. This frequently called as incipient motion, critical or scour. The criteria for motion may be explained in several ways [1]; with velocity approach, shear stress equations lift force mechanism. These might appear different but they can possibly connected principles. However, none these approaches seems explain frictional resistance characteristics an erodible form explicit like that universal laws developed by Nikuradse [2]. aim this paper bring out such direct relationship between DarcyWeisbach friction factor, λ, energy slope, S, along other variables submerged unit weight particles, fluid etc. It shown equation could obtained indirectly using classical data sand roughened pipes [2] used Vanoni [3] while establishing Shields’ curve. In study beds under free surface flows considered.

参考文章(3)
Vito A. Vanoni, Measurements of critical shear stress for entraining fine sediments in a boundary layer California Institute of Technology. ,(1964)
Walter H. Graf, Hydraulics of Sediment Transport ,(1984)
J. Nikuradse, Laws of Flow in Rough Pipes ,(1950)