A study of the effect of liquid viscosity on density-driven wet granular segregation in a rotating drum

Abstract

Experiments were conducted for this study to investigate the effects of liquid viscosity on density-induced granular segregation in a thin rotating drum. The goal of this study is to ultimately quantify the effect of the liquid bridge force on density-induced granular segregation. The movements of the granular materials were recorded by high-resolution and high-speed cameras. Image processing technology and particle tracking methods were applied to measure the segregation index, velocities, the fluctuation velocity and granular temperatures of heavy particles. The results of the experiment indicate that by adding small amounts of liquid with varying viscosities the segregation behavior and dynamic properties of wet granular materials are significantly influenced due to the formation and rupturing of liquid bridges. The segregation behavior is mitigated with the viscosity of the liquid due to the energy dissipation caused by the formation and rupturing of the liquid bridges that increase as liquid viscosity increases. The correlation between the intensity of the segregation and the angle of repose is also discussed in this study.