Rheology and microstructure in concentrated noncolloidal suspensions
Rheology and microstructure in concentrated noncolloidal suspensions
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DOI：
10.1122/1.1501925
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发表时间：
2002-09-01
影响因子：
3.3
通讯作者：
Brady, JF
中科院分区：
文献类型：
--
作者：
Sierou, A;Brady, JF
用加速斯托克斯动力学方法研究了非布朗粒子单分散悬浮液在弱相互作用力作用下的简单剪切流变行为。一个更快的数值算法的可用性允许调查较大的系统（通常为512个颗粒），和准确的结果，悬浮液粘度，第一和第二法向应力差，和颗粒压力被确定为体积分数的函数。系统的微观结构，表示通过对分布函数，也进行了研究，并演示了如何在对分布函数的各向异性与悬浮液的非牛顿行为。正常的过度剪切应力的比率被发现是一个递增的函数的体积分数，这表明不同的体积分数缩放的应力张量的不同元素。改变颗粒间力的相对强度和范围，并分析其对剪应力和正应力的影响。平衡冻结体积分数（φ约0.494）以上的体积分数也进行了研究，它被发现，该系统表现出强烈的倾向，以秩序下流动的体积分数低于硬球玻璃化转变;有限的结果为φ = 0.60，但是，表明该系统再次剪切下无序。(C)2002年，流变学学会。
The rheological behavior of a monodisperse suspension of non-Brownian particles undergoing simple shear flow in the presence of a weak interparticle force is studied using accelerated Stokesian dynamics. The availability of a faster numerical algorithm permits the investigation of larger systems (typically of 512 particles), and accurate results for the suspension viscosity, first and second normal stress differences, and the particle pressure are determined as a function of the volume fraction. The system microstructure, expressed through the pair-distribution function, is also studied and it is demonstrated how the resulting anisotropy in the pair-distribution function is correlated with the suspension non-Newtonian behavior. The ratio of the normal to excess shear stress is found to be an increasing function of the volume fraction, suggesting different volume fraction scalings for different elements of the stress tensor. The relative strength and range of the interparticle force is varied and its effect on the shear and normal stresses is analyzed. Volume fractions above the equilibrium freezing volume fraction (phi approximate to 0.494) are also studied and it is found that the system exhibits a strong tendency to order under flow for volume fractions below the hard-sphere glass transition; limited results for phi = 0.60, however, show that the system is again disordered under shear. (C) 2002 The Society of Rheology.