Slip, Concentration Fluctuations, and Flow Instability in Sheared Polymer Solutions
Slip, Concentration Fluctuations, and Flow Instability in Sheared Polymer Solutions
复制标题
剪切聚合物溶液中的滑移、浓度波动和流动不稳定性
DOI：
--
复制
发表时间：
2001
期刊：
影响因子：
--
通讯作者：
M. Graham
中科院分区：
文献类型：
--
作者：
W. Black;M. Graham
最近的实验表明，聚合物溶液中剪切增强的浓度波动的增长受到固体边界的强烈影响。我们分析了剪切聚合物溶液模型的动力学，考虑了应力变化对质量通量和壁滑移的影响。当（且仅当）这些效应存在时，流动表现出与实验观察一致的边界局部不稳定性。即使在没有流动不稳定性的情况下，热驱动的浓度波动在边界附近也显著增强。
Recent experiments suggest that shear-enhanced growth of concentration fluctuations in polymer solutions is strongly influenced by solid boundaries. We analyze the dynamics of a model of a sheared polymer solution, accounting for the effect of stress variations on mass flux and for wall-slip. If (and only if) these effects are present, the flow exhibits a boundary-localized instability consistent with experimental observations. Even in the absence of flow instability, thermally-driven concentration fluctuations are significantly enhanced near the boundary.