Rise of an intruder disk under tapping

UÑAC, R.O.; VIDALES, A. M.; L.A. PUGNALONI

La Plata

Workshop; Workshop in the PASI 2014: Grand Challenges in Particulate Media: From Granular Media to Colloids and Active Matter; 2014

National Science Foundation

The problem of the segregation effect (induced by a tapping operation) of a big particle submerged in a bath of small ones is an old problem. In particular, the case of the ascending run of a big disk in a column of small disks subjected to tapping has a number of questions yet to be answered: how do arches between disks affect the rise of the intruder?. Does the fact that the intruder reaches the surface depend on the relationship between the depth at which it is initially found and the crystallization process induced by tapping? We present simulations using a pseudo molecular dynamic algorithm to ansewr the above questions. The parameters involved are the relative size of the intruder respect to the bath of small particles, the amplitude of the tapping and the initial position at which the intruder begins its run. During all the tapping process we record the statistic on the formation of arches between disks, i.e., we characterize the size, number and type of the arches as a function of the tapping number and relate these quantities with the different parameters. We also record the final heigh of the intruder and try to assess the results with some simple theoretical approximations. Answers to the questions above are discussed.