Lees-Edwards boundary conditions for the multi-sphere discrete element method
Lees-Edwards boundary conditions for the multi-sphere discrete element method
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DOI：
10.1016/j.powtec.2021.05.025
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发表时间：
2021-09
影响因子：
5.2
通讯作者：
Nathan Berry;Yonghao Zhang;S. Haeri
中科院分区：
文献类型：
--
作者：
Nathan Berry;Yonghao Zhang;S. Haeri
本文提出了一种适用于多球离散元法的一致的Lees-Edwards边界条件，它可以在体元和微结构层次上减轻各种非物理效应。这些影响包括非线性的速度分布和不均匀的颗粒分布，这导致相对于压力和颗粒温度的显着误差。为了允许公平评估不同的实现方式，设计了一种新的复合球形颗粒形状，用于与从球形颗粒系统生成的可靠基准数据进行比较。多球离散元法被用来检查这些条件的两个实现。常用的朴素方法导致上述非物理效应，这些非物理效应是导致与基准结果的偏差高达一个数量级的数值伪影。同时，所提出的一致性实现满足Lees-Edwards边界条件的基本要求，并产生与基准结果以及现有文献非常一致的数据。通过比较上述方法，给出了多球离散元法中Lees-Edwards边界条件的一般实现原则。
A consistent implementation of Lees-Edwards boundary conditions is proposed for the Multi-Sphere Discrete Element Method, which can mitigate various unphysical effects at the bulk and micro-structural levels. These effects include non-linear velocity profiles and inhomogeneous particle distributions, which result in significant errors with respect to pressure and granular temperature. In order to allow for a fair assessment of different implementations, a novel compound sphere particle shape is devised for comparison to reliable benchmark data generated from systems of spherical particles. The Multi-Sphere Discrete Element Method is utilised to examine two implementations of these conditions. The commonly used Naive approach results in the aforementioned unphysical effects, which are numerical artefacts causing deviations from the benchmark results of up to one order of magnitude. Meanwhile, the proposed consistent implementation fulfils the fundamental requirements of Lees-Edwards boundary conditions and produces data which are in excellent agreement with the benchmark results, as well as the available literature. Comparing the aforementioned implementations, general principles are developed for implementing Lees-Edwards boundary conditions for the Multi-Sphere Discrete Element Method.