3D Numerical Model of the Spherical Particle Saltation in a Channel with a Rough Fixed Bed

Abstract

The paper describes a 3D numerical model of the spherical particle saltation. Two stages of particle salta- tion were distinguished – the particle free motion in water and the particle-bed collision. The particle mo- tion consists of the translational and rotational particle motion. A stochastic method of calculation of the particle-bed collision was developed. The collision height and the contact point were defined as random variables. Impulse equations were used and the translational and angular velocity components of the mov- ing particle immediately after the collision were expressed as functions of the velocity components just be- fore the collision. The dimensionless coefficients of the drag force and drag torque were determined as functions of both translational and rotational Reynolds numbers. The model is in good agreement with known experimental data. Examples of calculation of the particles’ lateral dispersion and the mean absolute values of the deviation angle of the particle trajectory are presented. KEY