2D Numerical model of particle-bed collision in fluid-particle flows over bed

• Published in: Journal of hydraulic research Vol. 44; no. 1; pp. 70 - 78
• Main Authors: Lukerchenko, Nikolai, Chara, Zdenek, Vlasak, Pavel
• Format: Journal Article
• Language: English
• Published: Delft Taylor & Francis Group 01.01.2006; International Association for Hydraulic Research
• Subjects: bed roughness; collision angle; Earth sciences; Earth, ocean, space; Exact sciences and technology; Hydrology. Hydrogeology; particle-bed collision; Saltation; canals; rotation; digital simulation; collision angle; transport; velocity; overthrust; saltation; particle-bed collision; slip; roughness; numerical models; bed roughness; sulfur; stochastic processes
• ISSN: 0022-1686; 1814-2079
• DOI: 10.1080/00221686.2006.9521662

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