DEM study of segregation degree and velocity of binary granular mixtures subject to vibration

This paper presents a study on the Brazil-nut segregation of binary granular mixtures under vibration by the discrete element method. The ascending velocity of large particles (Va) and the overall segregation degree (Dsep) are correlated to the vibration velocity amplitude (Vb) and the dimensionless frequency (fd). Both Dsep and the average Va increase linearly with Vb under a given fd, while the coefficient shows a critical change at fd =1. Va conforms to a single-peak distribution, and the shape parameters of the distribution converge after Vb > 1.7. Both Va and Dsep can be correlated to (A/ds)‧fd0.5 universally, where A is amplitude and ds is the small particles size. The increase of the volume fraction of large particles leads to the increase of Dsep and Va, which is probably linked with the increase in granular temperature and the difference between the vibration patterns of large and small particles.