Séminaire de Mécanique d'Orsay

Le Jeudi 27 juin à 14h00 - Salle de conférences du FAST

From mixing to segregation in a tapped column of bi-disperse wet disks

Ana Maria Vidales
INFAP, Univ. Nacional de San Luis, Argentine

We present a complete numerical study of the evolution of the segregation patterns obtained when tapping a column of disks of two different sizes. Simulations are performed using a pseudo-dynamic model that only takes into account the excluded volume restriction during the collision of the disks. The presence of humidity between the contacts is allowed through a sticking probability, whose maximum value is related to the wetting degree of the system. A mix of small and large disks with a given concentration is initially deposited in a rectangular die. The tapping procedure is achieved by expanding the particles and, then, by allowing them to fall down, due to gravity. The evolution of the tapped system is followed by measuring a set of segregation indices as a function of concentration and wetting degree. We also follow the behavior of the arches of particles present during the setting up of segregation. The incidence that geometrical restrictions and humidity have on segregation is analysed. We also compare our results with experiments belonging to other authors.