Viscoelastic Taylor-Couette instability of shear banded flow.
Viscoelastic Taylor-Couette instability of shear banded flow.
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DOI：
10.1103/physrevlett.104.198303
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发表时间：
2009-12
影响因子：
8.6
通讯作者：
S. Fielding
中科院分区：
文献类型：
--
作者：
S. Fielding
我们研究平面和弯曲库埃特几何形状中的数值剪切带流。我们的目标是捕获在涡度方向上堆叠的滚动单元的剪切带系统中的两个最新观察结果，与带之间界面的波动相关。根据泡孔曲率的程度和材料的本构特性，我们发现（i）由穿过其的第二法向应力跳跃驱动的带之间界面的不稳定性，或（ii）由其中大的第一法向应力驱动的高剪切带中的体粘弹性泰勒-库埃特不稳定性。两者都会导致滚动细胞和界面波动，但在每种情况下都具有不同的特征，从而表明最近每个实验中的滚动细胞起源不同。
We study numerically shear banded flow in planar and curved Couette geometries. Our aim is to capture two recent observations in shear banding systems of roll cells stacked in the vorticity direction, associated with an undulation of the interface between the bands. Depending on the degree of cell curvature and on the material's constitutive properties, we find either (i) an instability of the interface between the bands driven by a jump in second normal stress across it or (ii) a bulk viscoelastic Taylor-Couette instability in the high shear band driven by a large first normal stress within it. Both lead to roll cells and interfacial undulations but with a different signature in each case, thereby suggesting that the roll cells in each of the recent experiments are different in origin.