Verification and exploration of LAMMPS granular simulation software.

摘要

The use of granular media for engineering applications is very common, but it often leads to problems inducing or sustaining flow. There is a fair amount of information in regards to steady state flow of granular media, but less research can be found on the mixing and transient flow of media on a per granule basis. This research utilized a molecular dynamics simulator software, LAMMPS, to study the interactions of flowing granules and explore the ability of the software to simulate such an environment. The LAMMPS software was utilized to examine the position and velocity of particles on a per granule basis in a rotational mixing tumbler system. The timestep, tumbler cross section, and tumbler depth were varied during the simulations. The results showed that the amplitude of fluctuations in top layer flow velocity decreased as the number of sides of the tumbler increased, approaching the uniformity in top layer flow of a circular tumbler. Expansions into three dimensional space showed similar results to the two dimensional systems. This research showed that LAMMPS can be utilized as a valuable tool to understand the complex interactions of granular flow systems without the substantial cost of experimental equipment required to be able to track the interactions in granular systems with to the level of complexity that LAMMPS is capable of.