Shear banding and interfacial instability in planar Poiseuille flow

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• 作者：Suzanne M. Fielding ; Helen J. Wilson
• 关键词：Shear banding ; Interfacial instability ; Poiseuille flow
• 刊名：Journal of Non-Newtonian Fluid Mechanics
• 出版年：2010
• 出版时间：March 2010
• 年：2010
• 卷：165
• 期：5-6
• 页码：196-202
• 全文大小：682 K

文摘

Motivated by the need for a theoretical study in a planar geometry that can easily be implemented experimentally, we study the pressure driven Poiseuille flow of a shear banding fluid. After discussing the “basic states” predicted by a one-dimensional calculation that assumes a flat interface between the bands, we proceed to demonstrate such an interface to be unstable with respect to the growth of undulations along it. We give results for the growth rate and wavevector of the most unstable mode that grows initially, as well as for the ultimate flow patterns to which the instability leads. We discuss the relevance of our predictions to the present state of the experimental literature concerning interfacial instabilities of shear banded flows, in both conventional rheometers and microfluidic channels.