Hydrodynamic, translational diffusion in fiber suspensions subject to simple shear flow
Hydrodynamic, translational diffusion in fiber suspensions subject to simple shear flow
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纤维悬浮液中受简单剪切流影响的流体动力学平移扩散
DOI：
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
C. Cohen
中科院分区：
文献类型：
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作者：
Mani Rahnama;D. Koch;Yoichi Iso;C. Cohen
计算了纤维和流体颗粒在纤维悬浮液中经历简单剪切流动时的平移和流体动力扩散系数。纤维之间的流体动力相互作用用细长体理论处理。扩散系数是通过对所有可能的相互作用求平均得到的。对稀释液(n13-≪-1)和半稀释液(n13-≫-1，但n13-d-≤-1)进行了研究。这里，n是单位体积的纤维数，L是纤维长度，d是纤维直径。在一项补充实验研究中，在圆柱形Couette池中观察到了折射率和密度匹配的半稀薄纤维悬浮液中示踪剂颗粒的位置。接近理想流体颗粒的示踪小球的有效扩散系数随纤维浓度呈近似线性增长，与理论预测基本一致。实验测得的扩散系数比理论预测值小约20%-45%。
Translational, hydrodynamic diffusivities for fibers and fluid particles in a suspension of fibers undergoing simple shear flow have been calculated. The hydrodynamic interactions between the fibers were treated using slender‐body theory. The diffusivities were obtained by averaging over all possible interactions. Both dilute (nl3≪1) and semidilute (nl3≫1 but nl2d≤1) suspensions were studied. Here, n is the number of fibers per unit volume, l is the fiber length, and d is the fiber diameter. In a complementary experimental study, the positions of tracer particles were observed in an index of refraction and density matched semidilute fiber suspension in a cylindrical Couette cell. The effective diffusivity of small tracer spheres that approximated ideal fluid particles exhibited an approximate linear growth with fiber concentration in qualitative agreement with the theoretical predictions. The experimentally measured diffusivities were smaller than the theoretical predictions by about 20%–45%.