Random packing dynamics of $\Sigma_{2v}(2\pi/3)$-triplets

TL;DR

This study investigates the packing behavior of bent triplet particles resembling water molecules using DEM and multi-sphere methods, analyzing how long-range forces influence packing density, structure, and force distributions.

Contribution

It introduces a novel simulation approach combining DEM and multi-sphere methods to study the packing dynamics of $ ext{C}_{2v}$ symmetric triplets with long-range interactions.

Findings

Packing density varies with interaction strength.

Radial distribution functions reveal structural organization.

Force distributions show characteristic probability patterns.

Abstract

In this letter, we used a combination of DEM and the multi-sphere method to investigate the random packing dynamics of $\Sigma_{2v}(2\pi/3)$-triplets. These triplets consist of three overlapping primary spheres, forming a bent structure with a bond angle of $2\pi/3$ and belonging to the $C_{2v}$ symmetry group. The selection of this specific structure was motivated by its similarity to molecules such as water, which displays crucial physicochemical properties and finds extensive application in various fields. To ensure non-overlapping particles at the beginning of the simulations, the rectangular confinement box was divided into basic cells. Each triplet was then inserted into a basic cell with a random orientation. After that, the system is allowed to settle under gravity towards the bottom of the box. An implicit leapfrog algorithm with quaternion acceleration was used to numerically integrate the rotational motion equations. By assuming a molecular approach, we account for the long-range cohesive forces using a Lennard-Jones (LJ)-like potential. The packing processes are studied assuming different long-range interaction strengths. We performed statistical calculations of the different quantities studied including packing density, radial distribution function, and orientation pair correlation function. In addition, the force probability distributions in the random packing structures have been analyzed.