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arXiv · 2410.14798

Improved Velocity-Verlet Algorithm for the Discrete Element Method

Dhairya R. Vyas·Julio M. Ottino·Richard M. Lueptow·Paul B. Umbanhowar
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Abstract

The Discrete Element Method is widely employed for simulating granular flows, but conventional integration techniques may produce unphysical results for simulations with static friction when particle size ratios exceed $R \approx 3$. These inaccuracies arise because some variables in the velocity-Verlet algorithm are calculated at the half-timestep, while others are computed at the full timestep. To correct this, we develop an improved velocity-Verlet integration algorithm to ensure physically accurate outcomes up to the largest size ratios examined ($R=100$). The implementation of this improved integration method within the LAMMPS framework is detailed, and its effectiveness is validated through a simple three-particle test case and a more general example of granular flow in mixtures with large size-ratios, for which we provide general guidelines for selecting simulation parameters and accurately modeling inelasticity in large particle size-ratio simulations.

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Dhairya R. Vyas, Julio M. Ottino, Richard M. Lueptow, Paul B. Umbanhowar. 2024-10-18. Improved Velocity-Verlet Algorithm for the Discrete Element Method. https://arxiv.org/abs/2410.14798

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