2013 Volume 46 Issue 3 Pages 187-195
A method for analyzing quantitatively the effects of particle shape and size distribution on the size segregation of particles using Distinct Element Method simulation, which employ spherical particles with an equivalent friction coefficient to efficiently incorporate the effect of particle shape, is proposed. The simulation of container filling is carried out for particles having a continuous particle size distribution, including different particle shapes and geometric standard deviations σg. In order to quantitatively evaluate the particle size segregation into the active layer, two metrics are used: a new segregation index indicating the degree of segregation and the percolation index, which evaluates the percolation segregation. Using spherical grass beads, and irregular-shaped Ise sand and alumina particles, the filling behavior of particles into a container are simulated, and the segregation index of those filling layer are estimated. Although increasing the irregularity of particles reduce the mobility of particles, the segregation index of those filling layer conversely became large. Further when the size distribution is wider, the segregation of fine particles increases considerably, but the segregation indexes of coarse particles do not vary; moreover, the high index values of the fine particles become smallest for a σg of around 1.38.
