School of Mechanical Engineering Gregory Bolshak

SCHOOL OF MECHANICAL ENGINEERING SEMINAR

Monday, January 2, 2019 at 14.00

Wolfson Building of Mechanical Engineering, Room 206 

Kinetically-Constrained Models for Granular Clogging

Gregory Bolshak

 M. Sc. student of Prof. Yair Shokef

The kinetically-constrained Kob-Andersen model has proven to be efficient in describing granular matter close to jamming. The model allows to calculate numerically the current of particles propagating through a lattice, the particle density distribution and even evaluate spatial correlations between the particles and the effect of these correlations on measurable parameters such as current. This simple model also allows to analytically predict the probability of the system to be in a jammed state, or to detect particles that will never be able to move.

We simulate the movement of granular matter through an opening, when subjected to a constant gravitational field. We want to study the behavior as a function of opening size, particle density and the acceleration of gravity (external field). To that end, we constructed a computationally-efficient Monte-Carlo simulation, which implements a rejection-free algorithm. We also study the model without any obstacles with periodic boundary conditions (the bulk model). We have built a mean-field theory for this model and we see from the simulations that correlations break mean-field behavior and give rise to non-monotonic behavior of current as a function of the driving field. From the numerical simulations we see that lateral flow decreases the local density in front of the hole, but the current through the hole can be described using the bulk behavior at that local, reduced density.