Disk-Shaped Particle Motion in Shear Fields, 1991 Forest Products Symposium Proceedings

The motion of disk-shaped particles in a shear flow is modeled using a Stokesian dynamics technique. Algebraic expressions from lubrication theory are used to estimate the hydrodynamic interactions between particles and between particles and boundaries. Mechanical forces are added when the particle surfaces approach closer than a given “surface roughness”. The motion of the particles and the combined forces of the particles on the boundaries are obtained from the model.

Particles near a solid boundary need to “push” themselves away. before rotation; mechanical interactions occur when the particles have any significant surface roughness. When mechanical interactions are modeled, the behavior of the disks resemble the experimental results for rods near solid boundaries. Concentrated suspensions decrease the tendency for particle rotation. However, when particles do rotate, large scale structures are formed between the boundaries; these structures create large tangential and normal forces.