水平摆振下环形巴西果分离效应模拟研究

为了研究水平摆振下混合颗粒体系的分离行为及其机理,利用离散单元法进行数值模拟,对二元混合颗粒振动下的运动行为进行了研究,观察到圆筒形容器内一种新的分离现象,即"环形巴西果"分离。通过对比不同振动参数、不同区域内混合颗粒体系的运动特性,分析了颗粒的整体流态、能量、离心力作用以及颗粒间的力链结构强度,对混合颗粒的中心偏析、边界堆积以及整体分离行为,揭示了"环形巴西果"分离构型的内在机理。结果表明:频率为1Hz、振幅为160°时,混合颗粒出现"环形巴西果"分离现象;频率为3Hz、振幅为40°时,混合颗粒出现"巴西果"分离现象,且通过调整振幅和频率可以控制中心区域大颗粒偏析程度,实现"环形巴西果"分离构型与"巴西果"分离构型之间的转换。

Simulation study of annular Brazil nut separation effect under horizontal rotational oscillation

In order to study the separation behavior and mechanism of mixed particle system under horizontal rotational oscillation,the discrete element method is used to carry out numerical simulation and study the movement behavior under vibration of binary mixed particles.A new separation phenomenon,"Annular Brazil-nut"separation,is observed in the cylindrical container.By comparing the motion characteristics of the mixed particle system in different vibration parameters and different regions,the central segregation,boundary accumulation and overall separation behaviors of the mixed particles are deeply explored from the overall flow state,energy,centrifugal force and strength of force chain structure between the particles.The internal mechanism of the separation phenomenon of"Annular Brazil-nut"is revealed.The results show that when the frequency is 1 Hz and the amplitude is 160°,the mixed particles appear in the"Annular Brazil-nut"separation phenomenon.When the frequency is 3 Hz and the amplitude is 40°,the mixed particles appear"Brazil-nut"separated phenomenon and by adjusting the amplitude and frequency can control the degree of large particle segregation in the central region,and achieve conversion between"Annular Brazil-nut"separation configuration and"Brazil-nut"separation configuration.