In many granular material simulation applications, DEM capability is focused on the dynamic solid particulate flow properties and on systems in which millions of particles are involved. The time of relevance is many seconds or even minutes of real time. Simplifying assumptions are made to achieve run completion in practical timescales. There are certain applications, typically involving manufactured particles, where a representative pack is of the order of a thousand particles. More accurate capturing of the influence of complex shape is then often possible. Higher accuracies are necessary to model the topology of the void space, for example, for further CFD simulation and optimisation of fluid flow properties. Alternatively, the accuracy may be critical for structural performance and the force or stress transmission through the contact points is to be controlled to avoid material damage and poor function. This paper briefly summarises methods for simulation of shape effects on packing structures in the granular community and narrows the scope to problems where shape effects are of overriding concern. Two applications of mono-sized, mono-shaped packing problems are highlighted: catalyst support pellets in gas reforming and concrete armour units in breakwater structures. The clear advantages of FDEM for complex-shaped particle interactions in packed systems with relatively few particles are discussed. A class of particulate problems, ‘FDEM-suited’ problems, ones that are ideal to be solved by FDEM rather than by DEM, is proposed for science and engineering use.

在许多颗粒材料模拟应用程序中，DEM功能集中于动态固体颗粒流动特性以及涉及数百万个颗粒的系统。相关时间是几秒钟甚至几分钟的实时时间。为了在实际时间范围内完成运行而做出了简化的假设。在某些应用中，通常涉及人造颗粒，其中代表性包装的数量约为一千个颗粒。这样通常可以更准确地捕获复杂形状的影响。较高的精度对于建模空隙空间的拓扑是必要的，例如，对于进一步的CFD模拟和流体流动特性的优化。或者，精度对于结构性能可能至关重要，并且应控制通过接触点的力或应力传递，以避免材料损坏和功能不良。本文简要总结了模拟形状对颗粒群落中堆积结构的影响的方法，并将范围缩小到形状影响最为重要的问题。强调了单一尺寸，单一形状填充问题的两种应用：气体重整中的催化剂载体颗粒和防波堤结构中的混凝土装甲单元。讨论了FDEM对于颗粒相对较少的堆积系统中复杂形状的颗粒相互作用的明显优势。针对科学和工程应用，提出了一类微粒问题，即“ FDEM合适”问题，非常适合通过FDEM而不是DEM解决。