Patterns of convection and distribution of binary particles under vibration and airflow

Granular matter exists widely in nature and engineering practice and exhibits abundant and complex phenomena of convection and separation. Here, we focus on the pattern of convection and distribution of binary particles under vibration and airflow. Various patterns of convection and distribution were observed. It's found that the convection of binary particles shows four patterns that are similar, but not identical to those in the mono-component granular system. The same pattern of particle convection is often obtained with different particle distribution patterns in different cases of vibration and airflow, and one of distribution patterns tends to appear with the same convection pattern. The pattern of particle convection has an important influence on the pattern of particle distribution. These findings are expected to have implications for a basic understanding of the convection and separation phenomena of granular material.