Air-Driven Segregation in Binary Granular Mixtures with Same Size but Different Densities  

作　　者：鲁长宠 史庆藩 杨雷 孙刚 

机构地区：[1]Department of Physics, Beijing Institute of Technology, Beijing 100081 [2]Institute of Physics, Chinese Academy of Sciences, Beijing 100080

出　　处：《Chinese Physics Letters》2008年第7期2542-2545,共4页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant Nos 10675018 and 10674157

摘　　要：We investigate the segregation effect of binary granular mixtures with the same size but different densities under vibration at different air pressures. Our experiments show that the segregation state is seriously dependent on the air pressure and there is a new type of partially segregated state at high air pressure, which has the characteristic that the lighter grains tend to stay at the bottom and form a pure layer, while heavier grains and remained lighter ones tend to rise and to form a mixed layer on the top of the system. We redefine the order parameter to study the variation of the segregation effect with the air pressure and vibration parameter in detail. Finally, the mechanism of the air-driven segregation is illustrated by the faster acceleration due to the airflow through the granular bed for lighter particles.We investigate the segregation effect of binary granular mixtures with the same size but different densities under vibration at different air pressures. Our experiments show that the segregation state is seriously dependent on the air pressure and there is a new type of partially segregated state at high air pressure, which has the characteristic that the lighter grains tend to stay at the bottom and form a pure layer, while heavier grains and remained lighter ones tend to rise and to form a mixed layer on the top of the system. We redefine the order parameter to study the variation of the segregation effect with the air pressure and vibration parameter in detail. Finally, the mechanism of the air-driven segregation is illustrated by the faster acceleration due to the airflow through the granular bed for lighter particles.

关 键 词：SEPARATION REVERSE CONVECTION VIBRATION PARTICLES 

分 类 号：O4[理学—物理]