Magnetic-Based Particle Tracking in a Dense Granular Shear Flow

Granular material is ubiquitous in nature and plays a significant role in industry. Researchers have paid a lot of attention to density and velocity distributions of dense granular flows. However, the motion of individual particle is hard to capture because visualizing individual particles in a dense granular flow, especially in 3D, is very difficult and could be expansive. Here we use the magnetic particle tracking (MPT) technique to capture the motion of a single particle in a sheared dense granular flow. The accuracy of MPT is quantified using experimental results. The sheared granular flow is generated in a Couette cell by rotating a plate at the bottom of a cylinder container. It is able to generate different shear stresses by controlling the speed of the plate. By tracking the magnetic particle in the cylinder, we can capture the velocity of an individual particle at different locations in the granular flow.