Influence of particle size distribution on 2D random close packing

The densest amorphous packing of rigid particles is known as random close packing (RCP). It is well known that higher RCP volume fractions are achieved by using collections of particles with a variety of sizes. The variety of sizes is often quantified by the polydispersity of the particle size distribution: the standard deviation of the radius divided by the mean radius.  Our prior work showed that for 3D packings, the skewness also plays an important role (related to the third moment of the size distribution).  In this talk, we present results from 2D packings with a variety of size distributions.  The behavior is somewhat different from the 3D results, but again we present an empirical formula that describes the RCP volume fraction data well across the variety of size distributions.