void elimination in granular simulation


I have a 2D hopper made of granular particle walls filled with granular particles of two sizes. Is there a way I can make the bottom silo walls vibrate so that the small particles fill the void spaces.

Generally is there a way i can completely eliminate the void spaces in the randomly closed packed structure of the grains in the silo(I have to calculate the areafracton of the grains which is fluctuating appreciably due to voids). I am using create_atoms command to fill the silo.

Thank you in advance for the advice



You could make your granular walls wiggle (even side ones), and friction may do the rest for a packed bed. All you really need to do is induce enough vibration so that particles can rearrange.

If you are using fix wall/granular then it has “wiggle”
and “shear” options which can be used to compactify
granular particles.