We performed experiments to measure the dynamic properties of wet granular matter in a rotating drum device. Four different amounts of liquid and rotation speeds were used in the experiments. The purpose was to quantify the effect of the cohesive force in the granular system. The results show that when only very small amounts of liquid were added, no liquid bridges formed. This is because the liquid was first trapped on the surface of the particles due to the particle roughness. When the volume fraction of the fluid became larger, liquid bridges formed on almost every particle. The results showed that the addition of liquid contents, and changing the rotation speed, both had a significant effect on the dynamic properties of granular matter. This was due to the hysteretic formation and rupturing of liquid bridges and the introduction of inertial force to the device. After the liquid bridges formed between all particles the average energy dissipation due to the hysteretic formation and rupturing of the liquid bridges increased with an increase in the liquid content. (C) 2011 Elsevier B.V. All rights reserved.
