Particle Velocity Development of Concentrated Suspension Fluid in Reversal Shear Flow

Abstract

In this study, we have focused on the relationship between the transient response generated with concentrated suspension of non-Brownian particles after shear-reversal and the individual particle velocity growths measured in the flow. The shear flows between two parallel plates were tested utilizing a suspension with volume fraction of 50 vol%. A pre-shear flow was applied for 30 seconds and then a rest time of 10 seconds was taken before the subsequent forward or backward flows. The motion of tracer particles were photographed and the particle velocities were estimated. The particle velocities had large fluctuations. Even under such conditions, it was concluded that the velocity growths measured in the subsequent backward flows were delayed in particular near the stationary plate even in the higher shear rate.