Resuspension due to vertical oscillations: experiments and numerical modeling

Abstract

Granular matter is present everywhere in our practical lives. In particular, the movement initiation due to an external excitation, like vibration, is responsible of the detachment of particles that can then be put in an air stream or be part of a pollution process with undesirable consequences. In those scenarios, the knowledge of the mechanisms for the initiation of particle movement is crucial to predict the removal probabilities. This paper focuses on the onset of the movement of particles placed on a horizontal surface subjected to a vertical sinusoidal mechanical vibration. The problem is tracked both experimentally and by DEM simulations. Millimeter glass and plastic spheres with a given size are deposited on a rough surface built with glued glass beads with different packing fractions (coverage). The critical values for the amplitude and the frequency of the vibration needed to start the movement of at least half of the particles on the surface are studied as a function of the properties of the mobile particles and the surface coverage. The results from experiments and simulations are in good agreement. They show that the size of the mobile particle plays the main role in the present problem. Second in relevance are the size ratio between the glued and the mobile particles and the coverage degree of the surface. Finally, the density of the material plays a minor role inside the range of values studied here.