中文摘要：

颗粒物质的混合是化学工业生产的重要单元操作,由于颗粒物质运动行为的复杂性,工业混合器中的颗粒运动规律及物理机制至今仍未被全面认识。作为一种精细的数值方法,离散单元法（discrete element method,DEM）在单颗粒尺度上描述颗粒物质的受力与运动行为,因此在研究混合机理方面具有独特优势。随着DEM模型与计算技术的快速发展,DEM已被广泛应用于各种混合过程的研究。通过DEM可以全面考察不同的颗粒性质、混合器类型以及操作条件等因素对混合机理的影响,从而对于指导粉体工业的生产操作及设备优化改进具有重要意义。本文重点阐述了DEM在无黏颗粒、黏结性颗粒、非球形颗粒混合过程模拟以及大规模计算等方面的最新进展,并对未来发展进行了展望。

英文摘要：

The mixing of granular materials is an important unit operation in many industries. Due to the complex behaviors of granular flows,general laws and fundamental mechanisms of granular flows in industrial mixers are not completely understood yet. As a detailed numerical approach,the discrete element method（ DEM） describes the forces and motions of granular materials at the particle scale,and thus has notable advantages over experimental approaches in the research of mixing mechanisms. With the rapid developments of its models and the computational technologies,this method becomes more and more popular in the simulations of various mixing processes. The effects of particle properties,mixer types,and operating parameters on mixing rate and mixing mechanisms could be investigated comprehensively through DEM,which would be quite valuable for the design and optimization of mixers as well as their optimal operations. Moreover,the high computational cost of industrial-scale simulations could be greatly alleviated by the fast developments of computer hardware, such as the advent of graphics processing unit（ GPU）. This review summarizes the recent progresses of DEM simulations on mixing,with emphasis on the treatments for non-cohesive particles in different kinds of mixers（ rotary and fixed）,cohesiveparticles（ fine and wet）,non-spherical particles（ direct description of shape and multi-sphere method）,and largescale implementations. Finally,future development of the DEM method in mixing simulations is prospected.