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arXiv · 1108.2731

Criterion for purely elastic Taylor-Couette instability in the flows of shear-banding fluids

M. A. Fardin·T. J. Ober·C. Gay·G. Grégoire·G. H. McKinley·S. Lerouge
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Abstract

In the past twenty years, shear-banding flows have been probed by various techniques, such as rheometry, velocimetry and flow birefringence. In micellar solutions, many of the data collected exhibit unexplained spatio-temporal fluctuations. Recently, it has been suggested that those fluctuations originate from a purely elastic instability of the flow. In cylindrical Couette geometry, the instability is reminiscent of the Taylor-like instability observed in viscoelastic polymer solutions. In this letter, we describe how the criterion for purely elastic Taylor-Couette instability should be adapted to shear-banding flows. We derive three categories of shear-banding flows with curved streamlines, depending on their stability.

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M. A. Fardin, T. J. Ober, C. Gay, G. Grégoire, G. H. McKinley, S. Lerouge. 2011-08-12. Criterion for purely elastic Taylor-Couette instability in the flows of shear-banding fluids. https://doi.org/10.1209/0295-5075%2F96%2F44004

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