Analytic model of the Brazil Nut Effect driven by void filling

Abstract

We proposed an analytic model for the void-filling mechanism to describe Brazil Nut Effect. The void-filling process attributes the rise of the 'intruder' particle to the filling, by small particles, of voids created momentarily beneath the intruder. The velocity of small particles entering the void was derived from the model for Janssen Effect. This approach allows the analytic determination of the dynamics of the intruder. Intruder rise velocity and position plots of published simulation and empirical results are reproduced. This work shows how the Janssen Effect can be used in describing the Brazil Nut Effect driven by void-filling.