Revisiting the stability of circular Couette flow of shear-thinning fluids
Revisiting the stability of circular Couette flow of shear-thinning fluids
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DOI：
10.1016/j.jnnfm.2012.06.002
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发表时间：
2012-09-01
影响因子：
3.1
通讯作者：
Ait-Messaoudene, Noureddine
中科院分区：
文献类型：
--
作者：
Alibenyahia, Brahim;Lemaitre, Cecile;Ait-Messaoudene, Noureddine
对具有和不具有屈服应力的剪切稀化流体的两个同轴圆柱体之间的库埃特流进行了三维线性稳定性分析。外筒固定，内筒旋转。使用三种流变模型：Bingham、Carreau 和幂律模型。探索了广泛的流变、几何和动力学参数。为 Carreau 流体提供了关键条件的新数据。在轴对称情况下，结果表明，当使用内壁剪切粘度定义雷诺数时，对于所有考虑的流体，剪切稀化会延迟泰勒涡旋的出现。结果表明，这种延迟是由于基值和扰动之间的能量交换减少所致，而不是由于粘性耗散的修改所致。在非轴对称情况下，与Caton [1]相反，我们没有发现任何不稳定性。 (C) 2012 Elsevier B.V. 保留所有权利。
Three-dimensional linear stability analysis of Couette flow between two coaxial cylinders for shear-thinning fluids with and without yield stress is performed. The outer cylinder is fixed and the inner one is rotated. Three rheological models are used: Bingham, Carreau and power-law models. Wide range of rheological, geometrical and dynamical parameters is explored. New data for the critical conditions are provided for Carreau fluid. In the axisymmetric case, it is shown that when the Reynolds number is defined using the inner-wall shear-viscosity, the shear-thinning delays the appearance of Taylor vortices, for all the fluids considered. It is shown that this delay is due to reduction in the energy exchange between the base and the perturbation and not to the modification of the viscous dissipation. In the non axisymmetric case, contrary to Caton [1], we have not found any instability. (C) 2012 Elsevier B.V. All rights reserved.