One of the systems we want to look at is what happens when clusters of particles collide with one another when adhesion is present. To get more natural clusters of particles if different particle sizes, material is placed in a cold distribution and allowed to collapse under its own self-gravity.
This first movie shows a simulation where the original distribution has a surface density of 1 g/cm^2.
Here is a movie which shows a simulation where the original distribution has a surface density of 10 g/cm^2.