Flow of magnetized grains in a rotating drum

G. Lumay and N. Vandewalle
Flow of magnetized grains in a rotating drum
Phys. Rev. E 82, 040301(R), 2010
DOI: https://doi.org/10.1103/PhysRevE.82.040301

Flow of magnetized grains in a rotating drum

We have experimentally investigated the influence of a magnetic interaction between the grains on the flow of a granular material in a rotating drum.

The magnetic cohesion is induced by applying a homogeneous external magnetic field B
oriented either parallel or perpendicular to the gravity g.
The drum rotating speed has been selected to obtain a continuous flow when the magnetic field is switched off.

We show that, for both magnetic field orientations, the cohesion is able to induce a transition
between the continuous flow regime to the discrete avalanche regime.
The avalanche dynamics is periodic when Bg and irregular when Bg.

Moreover, the maximal angle of stability θm increases strongly with the cohesion strength and could be higher than 90° when Bg.
A toy model based on the stability of a magnetic block on a magnetic inclined plane is proposed to explain this behavior.