Particle dynamics in dense shear granular flow  

作　　者：Dengming Wang Youhe Zhou 

机构地区：[1]Key Laboratory of Mechanics on Western Disaster and Environment, Ministry of Education of China, Lanzhou University, 730000 Lanzhou, China

出　　处：《Acta Mechanica Sinica》2010年第1期91-100,共10页力学学报（英文版）

基　　金：supported by the Key Project of the National Natural Science Foundation of China(10532040);the Programme of Changjiang Scholars and Innovative Research Team in University (IRT 0628)

摘　　要：The particle dynamics in an annular shear granular flow is studied using the discrete element method, and the influences of packing fraction, shear rate and friction coefficient are analyzed. We demonstrate the existence of a critical packing fraction exists in the shear granular flow. When the packing fraction is lower than this critical value, the mean tangential velocity profile exhibits a rate-independent feature. However, when the packing fraction exceeds this critical value, the tangential velocity profile becomes rate-dependent and varies gradually from linear to nonlinear with increasing shear rate. Furthermore, we find a continuous transition from the unjammed state to the jammed state in a shear granular flow as the packing fraction increases. In this transforming process, the force distribution varies distinctly and the contact force network also exhibits different features.The particle dynamics in an annular shear granular flow is studied using the discrete element method, and the influences of packing fraction, shear rate and friction coefficient are analyzed. We demonstrate the existence of a critical packing fraction exists in the shear granular flow. When the packing fraction is lower than this critical value, the mean tangential velocity profile exhibits a rate-independent feature. However, when the packing fraction exceeds this critical value, the tangential velocity profile becomes rate-dependent and varies gradually from linear to nonlinear with increasing shear rate. Furthermore, we find a continuous transition from the unjammed state to the jammed state in a shear granular flow as the packing fraction increases. In this transforming process, the force distribution varies distinctly and the contact force network also exhibits different features.

关 键 词：Shear granular flow - Tangential velocity profile Critical packing fraction Force distribution - Jammed state 

分 类 号：O357.52[理学—流体力学] TL501[理学—力学]