Author(s): Nikolai Lukerchenko; Zdenek Chara; Pavel Vlasak

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Keywords: Saltation; particle–bed collision; collision angle; bed roughness

Abstract: This paper deals with bed load transport and the movement of rotating spherical particles in an open channel flow is considered. A numerical model for the random process of the particle impact and rebound from the channel bed is developed. Stochastic methods of collision height and collision angle calculation are proposed. The velocity components of particle translational and angular movement of the particle immediately after collision are expressed as function of the particle translational and angular velocity components immediately before collision for two patterns of saltation process: impact with slip and impact without slip. The condition for the collision without slip is determined. Numerical simulation of particle saltation using this model of particle–bed collision is performed. It is shown that this model allows describing double collisions of the particle with a rough bed and that the mechanism of particle–rough bed collision supports sufficiently bed load transport in the form of saltation. In the case of smooth bed the particle jumps are quickly extinguished and after a few jumps the particle slides and rolls along smooth bed without jumps

DOI: https://doi.org/10.1080/00221686.2006.9521662

Year: 2006