An experimental and simulation study of dilute polymer solutions in exponential shear flow: Comparison to uniaxial and planar extensional flows
An experimental and simulation study of dilute polymer solutions in exponential shear flow: Comparison to uniaxial and planar extensional flows
复制标题
指数剪切流中稀聚合物溶液的实验和模拟研究：与单轴和平面拉伸流的比较
DOI：
10.1122/1.1346599
复制
发表时间：
2001
影响因子：
3.3
通讯作者：
E. Shaqfeh
中科院分区：
文献类型：
--
作者：
Thomas C. B. Kwan;Nathanael J. Woo;E. Shaqfeh
使用自由排水、柔性珠杆和珠弹簧链的布朗动力学模拟，比较稀聚合物溶液在指数剪切、单轴和平面拉伸流中的流变特性。我们引入了一种新颖的指数剪切应力函数，它使用消光角 χ 来考虑链在流动中对齐时的方向。将指数剪切启动和松弛期间的新应力函数与平面拉伸流中的 τ11−τ22 和单轴拉伸流中的 τ11−12(τ22+τ33) 进行比较，我们发现，对于这两个模型，三种不同的流在 Wi、应变和链长度的大范围内存在定量一致性。此外，最大延伸的分布表明，在所有模拟的 Wi 值下，所有三个流动中的链系综之间的微观结构等效，直至应变为 3 或 4。最后，我们展示了各种流程的实验和模拟之间的三个比较：（a）模拟......
The rheological properties of dilute polymer solutions in exponential shear, uniaxial, and planar extensional flows are compared using Brownian dynamics simulations of both freely draining, flexible bead-rod and bead-spring chains. We introduce a novel stress function for exponential shear which uses the extinction angle χ to take into account the orientation of the chain as it aligns in the flow. Comparing this new stress function during startup and relaxation in exponential shear with τ11−τ22 in planar extensional flow and τ11−12(τ22+τ33) in uniaxial extensional flow, we find that for both models there is a quantitative agreement among the three different flows over a large range of Wi, strain, and chain length. Furthermore, the distributions of maximum extension show a microstructural equivalence between ensembles of chains in all three flows up to strains of 3 or 4 at all values of Wi simulated. Finally, we show three comparisons between experiment and simulation of the various flows: (a) simulations ...