转动驱动圆角立方体颗粒有序堆积的离散元模拟

宏观颗粒体系的有序堆积研究可以为热系统中微观粒子的自组装提供研究模型,也有助于工业生产中提高颗粒材料的填充率.实验发现圆筒中的圆角立方体颗粒受容器往复旋转剪切作用会实现有序堆积.为探究旋转圆筒中立方体颗粒有序堆积过程的内部结构演化过程和动力学机理,采用超二次曲面方程构造了圆角立方体颗粒,基于离散元方法对旋转剪切作用下圆...

DEM SIMULATION OF ORDERING OF CUBES WITH ROUNDED CORNERS BY ROTATION DRIVEN

The study of the orderly packing of macroscopic particle can not only provide a research model for the self-assembly of microscopic particles in thermal systems but also help to imcrease the packing fraction of granular materials in industry. Experimental results showed that cubic particles with rounded corners subjected to alternating rotation of the cylinder would achieve orderly packing. In order to investigate the internal structure evolution and mechanism of the orderly packing process of cubic particles with rounded corners in rotational cylinders, the cubic particles with rounded corners are constructed by the superquadric surface equation. Numerical simulations are carried out to investigate the orderly packing process of cubic particles with rounded corners in the rotation cylinder based on discrete element method. The simulation reproduces the transition of cubic particles from the random packing state to the ordered dense packing state in the experiment, and gives the variation of packing fraction and cubatic order parameter with the increase of rotation number under different motion. The results show that the packing fraction and the cubatic order parameter to increase gradually with the increase of the number of rotation until a stable value. The orderly packing process of the system starts from the external particles to the inner particles gradually. By regulating the angular displacement of the cylinder, it is found that the characteristic number of alternating rotation for the particles to complete the orderly packing process is inversely proportional to the angular displacement of the cylinder. If the angular displacement is too low, the system will only form a structure with clusters of particles whose sides are parallel to the horizontal plane and clusters of particles whose diagonal of the face parallel to gravity. It is also found that cubic particles in a sub-gravity environment can also achieve orderly packing through the alternating rotation of the cylinder. The reduction of gravitational acceleration inhibits the transition from disordered to ordered packing of cubic particles.