Nonlinear dynamics of an interface between shear bands
Nonlinear dynamics of an interface between shear bands
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DOI：
10.1103/physrevlett.96.104502
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发表时间：
2006-03-17
影响因子：
8.6
通讯作者：
Olmsted, PD
中科院分区：
文献类型：
--
作者：
Fielding, SM;Olmsted, PD
在非局部Johnson-Segalman模型下，数值研究了二维平面剪切流中剪切带界面的非线性动力学。与最近的线性稳定性分析相一致，我们发现，最初平坦的界面是不稳定的，相对于小的起伏足够小的比例的界面宽度中心点到细胞长度L-X。不稳定性在有限振幅界面波动中饱和。对于减少中心点/L-x，这些经历了一个非平衡过渡，从简单的行进界面波与恒定的平均壁应力，周期性的波纹波与周期性的应力响应。当存在多个剪切带时，我们发现不稳定的界面动力学和应力响应表明低维混沌。
We study numerically the nonlinear dynamics of a shear banding interface in two-dimensional planar shear flow, within the nonlocal Johnson-Segalman model. Consistent with a recent linear stability analysis, we find that an initially flat interface is unstable with respect to small undulations for a sufficiently small ratio of the interfacial width center dot to cell length L-x. The instability saturates in finite amplitude interfacial fluctuations. For decreasing center dot/L-x these undergo a nonequilibrium transition from simple traveling interfacial waves with constant average wall stress, to periodically rippling waves with a periodic stress response. When multiple shear bands are present we find erratic interfacial dynamics and a stress response suggesting low dimensional chaos.