Shear Flow Properties of Semiconcentrated Fiber Suspensions
Shear Flow Properties of Semiconcentrated Fiber Suspensions
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半浓缩纤维悬浮液的剪切流动特性
DOI：
10.1122/1.549836
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发表时间：
1985
影响因子：
3.3
通讯作者：
R. Armstrong
中科院分区：
文献类型：
--
作者：
Miguel A. Bibbó;S. Dinh;R. Armstrong
本文测量了刚性纤维在牛顿溶剂中的离心悬浮液在稳态剪切流动开始时的剪切应力。每单位体积有n根长度为L的纤维。使用各种不同体积分数的纤维;纤维纵横比也不同。发现随机取向的纤维悬浮液的粘性阻力大约是当颗粒位于剪切平面中时观察到的阻力的（nL 3）倍。瞬态剪切应力的测量表明，流变性能取决于总应变，而不是单独的剪切速率或时间。实验是在间距为H的平行平板间的扭转流动中进行的，以确定H/L对测量特性的影响。发现当H/L>1时没有影响。提出了两种不同的模型来考虑H/L<1时的壁面效应。计算值与实测值吻合良好。
Measurements are reported for the shear stress of a semiconcentrated suspension of rigid fibers in a Newtonian solvent in the startup of steady shear flow. There are n fibers each of length L per unit volume. A variety of different volume fractions of fibers was used; the fiber aspect ratio was varied as well. It is found that the viscous resistance of a randomly oriented fiber suspension is roughly (nL3) times the resistance observed when the particles lie in the planes of shear. The transient shear stress measurements show the rheological properties depend on the total strain and not on shear rate or time separately. Experiments were done in torsional flow between parallel plates separated by distance H to determine the effect of H/L on the measured properties. It is found that there is no effect for H/L>1. Two different models are presented to account for wall effects for H/L<1. Good agreement is found between computed and measured values.