Biomass is a renewable and sustainable energy resource. Current design of biomass handling and feeding equipment leverage both experiments and numerical modeling. This paper reviews the state-of-the-art discrete element methods (DEM) for the flow of milled biomass (Part I), accompanied by a comprehensive review on continuum-based computational models (Part II). The present review on DEM is primarily focused on the features and suitability of various particle shape models for different types of milled biomass because particle shape is the predominant attribute controlling the flow behavior of complex-shaped granular material. The general strengths and weaknesses in the applicability of those models for the milled biomass modeling are summarized. In particular, comments are provided to balance the numerical model capabilities and the computational cost for the development of DEM models. To our best knowledge, this is the first-of-its-kind review on DEM specifically for biomass. Our study indicates that the current DEM models require further development, calibration, and validation based on a deep understanding of biomass particle contact mechanics and experimental data support before they can be reliably used for predictive simulations in handling and feeding systems.

中文翻译：

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研磨生物质流动的计算模型回顾：第一部分：离散颗粒模型

生物质是一种可再生和可持续的能源。当前的生物质处理和进料设备设计利用了实验和数值模型。本文回顾了研磨生物质流的最新离散元素方法（DEM）（第一部分），同时对基于连续体的计算模型进行了全面综述（第二部分）。本文对DEM的研究主要集中在针对不同类型的磨碎生物质的各种颗粒形状模型的特性和适用性，因为颗粒形状是控制复杂形状颗粒材料的流动行为的主要属性。总结了这些模型在碾磨生物质模型的适用性方面的一般优缺点。尤其是，提供注释以平衡数值模型功能和DEM模型开发所需的计算成本。据我们所知，这是专门针对生物质的DEM的同类评论。我们的研究表明，当前的DEM模型需要在对生物质颗粒接触力学和实验数据支持有深刻理解的基础上进行进一步的开发，校准和验证，然后才能将其可靠地用于处理和进料系统的预测模拟。