Preliminary investigation of elongational flow of dilute polymer solutions
Preliminary investigation of elongational flow of dilute polymer solutions
复制标题
稀聚合物溶液拉伸流动的初步研究
DOI：
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发表时间：
1976
期刊：
影响因子：
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通讯作者：
R. Landel
中科院分区：
文献类型：
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作者：
S. Peng;R. Landel
建立了一套无管虹吸装置，用于测量拉伸流。在这种装置中，液体被连续地吸入毛细管，在建立稳定的流动之后，管被提升到液面以上。对于粘弹性液体，流动继续，并且柱可以从储层提升。在毛细管入口处，多余液体的振荡珠聚集，这干扰了流动和测量。这可以通过仔细控制液柱高度来最小化。对于均匀溶液，柱是对称的，从液面到毛细管入口稳定地逐渐变细，没有膨胀。初步结果显示拉伸粘度是特鲁顿系数3η S 0的103倍，其中η S 0是零剪切速率剪切粘度，并且对变形速率具有非常强的依赖性。提出了一种浓度-拉伸-速率缩减变量格式。
A tubeless siphon apparatus has been set up to measure extensional flow. In this apparatus the liquid is continuously drawn into a capillary and, after steady flow has been established, the tube is raised above the liquid surface. With viscoelastic liquids the flow continues and a column can be lifted from the reservoir. At the capillary entrance an oscillating bead of excess liquid collects, which interferes both with the flow and the measurements. This can be minimized by careful control of the liquid column height. For homogeneous solutions the column is symmetrical and tapers steadily from the liquid surface to the capillary entrance, with no bulging. Preliminary results show tensile viscosities 103 times that of the Trouton coefficient 3ηS0, where ηS0 is the zeroshear‐Rate shear viscosity, and having a very strong dependence on deformation rate. A concentration‐stretch‐rate‐reduced variable scheme is proposed.