Abstract
This paper presents a molecular dynamics simulation of an experiment on the stability of a pile of glass beads in a rotating drum filled with a “humid” atmosphere. The experimental avalanche angles were found to be different whether the humidity came from water or heptane. These experimental results allow us to set the basic hypothesis of the modeling: in the heptane atmosphere the glass beads are connected by deformable liquid bridges, whereas in the case of a water atmosphere solid bridges form between the beads. The numerical calculations of the avalanche angle as a function of the undersaturated pressure of heptane or water are in good agreement with the experimental results.