A three-dimensional numerical simulation of particle motion in a pipe with a rough bed is presented. The simulation based on the Lattice Boltzmann Method (LBM) employs the hybrid diffuse bounce-back approach to model moving boundaries. The bed of the pipe is formed by stationary spherical particles of the same size as the moving particles. Particle movements are induced by gravitational and hydrodynamic forces. To evaluate the hydrodynamic forces, the Momentum Exchange Algorithm is used. The LBM unified computational frame makes it possible to simulate both the particle motion and the fluid flow and to study mutual interactions of the carrier liquid flow and particles and the particle–bed and particle–particle collisions. The trajectories of simulated and experimental particles are compared. The
Particle Tracking method is used to track particle motion. The correctness of the applied approach is assessed.
The paper deals with an experimental investigation of impacts of non-rotating spherical bodies on a flat, solid surface in water. The aim of the investigation was, using the PIV (Particle Image Velocimetry), method to analyze the velocity fields around the falling sphere which falls in an oblique direction. The experiments showed that the wake that forms behind the sphere is asymmetrical and that after the impact it continues its morion to the bottom, only along one side of the sphere, though. This non-symmetrical velocity field results in additional forces which push the sphere to the opposite direction than is the direction of the sphere motion just after the impact. and Obsahuje seznam literatury