Discrete particle simulations have become the standard in science and industrial applications exploring the properties of particulate systems. Most of such simulations rely on the concept of interacting spherical particles to describe the properties of particulates, although, the correct representation of the nonspherical particle shape is crucial for a number of applications. In this work we describe the implementation of clumps, i.e. assemblies of rigidly connected spherical particles, which can approximate given nonspherical shapes, within the \textit{MercuryDPM} particle dynamics code. \textit{MercuryDPM} contact detection algorithm is particularly efficient for polydisperse particle systems, which is essential for multilevel clumps approximating complex surfaces. We employ the existing open-source \texttt{CLUMP} library to generate clump particles. We detail the pre-processing tools providing necessary initial data, as well as the necessary adjustments of the algorithms of contact detection, collision/migration and numerical time integration. The capabilities of our implementation are illustrated for a variety of examples.

翻译：离散粒子模拟已成为科学和工业应用中研究颗粒系统特性的标准方法。大多数此类模拟依赖于球形颗粒相互作用的概念来描述颗粒特性，然而，对于众多应用而言，正确表示非球形颗粒形状至关重要。本文描述了在\textit{MercuryDPM}粒子动力学代码中实现团簇（即刚性连接的球形颗粒集合体）的方法，该团簇可近似模拟给定的非球形形状。\textit{MercuryDPM}的接触检测算法对多分散颗粒系统具有特别高的效率，这对于近似复杂表面的多层团簇至关重要。我们利用现有的开源\texttt{CLUMP}库生成团簇颗粒，并详细介绍了提供必要初始数据的预处理工具，以及接触检测、碰撞/迁移和数值时间积分算法的必要调整。通过多个示例展示了所实现方法的功能。