Particle pressure in sheared Brownian suspensions
Particle pressure in sheared Brownian suspensions
复制标题
剪切布朗悬浮液中的颗粒压力
DOI：
10.1122/1.2807443
复制
发表时间：
2008
影响因子：
3.3
通讯作者：
J. Morris
中科院分区：
文献类型：
--
作者：
Yevgeny Yurkovetsky;J. Morris
本文研究了计算模拟剪切流中布朗硬球悬浮液中颗粒相对体积应力或颗粒压力的各向同性贡献。颗粒压力被机械地定义为颗粒施加的负平均法向应力，即Π=−(1∕3)[Σ11+Σ22+Σ33]对于粘度流，其中1、2和3分别指流动、速度梯度和涡度方向。分析了颗粒压力与平衡渗透压的关系以及Π与颗粒迁移现象的关系。利用现有的流体动力学函数，通过Stokesian动力学技术模拟流动，对单分散球形颗粒的颗粒体积分数在0.1≤φ≤0.52范围内的颗粒压力进行了评估。布朗运动与剪切运动的相对强度由Peclet数Pe=γa2∕D0给出，其中，γ为简单剪切流的剪切速率，a为球形颗粒半径，D0=kT∕6πηa。
The isotropic contribution of the particle phase to the bulk stress, or the particle pressure, is studied for Brownian hard sphere suspensions in computationally simulated shear flow. The particle pressure is mechanically defined as the negative mean normal stress exerted by the particles, i.e., Π=−(1∕3)[Σ11+Σ22+Σ33] for a viscometric flow where 1, 2, and 3 refer to the flow, velocity gradient, and vorticity directions, respectively. Analysis is provided to relate the particle pressure to the equilibrium osmotic pressure and to show the relation of Π to particle migration phenomena. Utilizing existing hydrodynamic functions and simulating the flow by the Stokesian Dynamics technique, the particle pressure is evaluated for particle volume fractions in the range 0.1⩽ϕ⩽0.52 for monodisperse spherical particles. The relative strength of Brownian to shearing motion is given by the Peclet number Pe=γa2∕D0, where γ is the shear rate of a simple shear flow, a is the spherical particle radius, and D0=kT∕6πηa wit...