Influence of Shear-Thinning Rheology on the Mixing Dynamics in Taylor-Couette Flow
Influence of Shear-Thinning Rheology on the Mixing Dynamics in Taylor-Couette Flow
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DOI：
10.1002/ceat.201900015
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发表时间：
2019-08-01
影响因子：
2.1
通讯作者：
Balabani, Stavroula
中科院分区：
文献类型：
--
作者：
Cagney, Neil;Balabani, Stavroula
非牛顿流变学可以对混合效率产生显著影响，这仍然知之甚少。采用粒子图像测速技术和流动显示技术相结合的方法，研究了剪切变稀对Taylor-Couette反应器内流体流变特性的影响。剪切变薄被发现改变临界雷诺数的泰勒涡的形成和高阶波动不稳定性，并与轴向波长的增加。强剪切稀化和弱粘弹性也可以导致波长的突变，因为雷诺数是变化的。最后，它示出，剪切变稀引起的涡流内的混合时间的增加，由于减少其循环，但提高了反应器中的流体的轴向分散。
Non-Newtonian rheology can have a significant effect on mixing efficiency, which remains poorly understood. The effect of shear-thinning rheology in a Taylor-Couette reactor is studied using a combination of particle image velocimetry and flow visualization. Shear-thinning is found to alter the critical Reynolds numbers for the formation of Taylor vortices and the higher-order wavy instability, and is associated with an increase in the axial wavelength. Strong shear-thinning and weak viscoelasticity can also lead to sudden transitions in wavelength as the Reynolds number is varied. Finally, it is shown that shear-thinning causes an increase in the mixing time within vortices, due to a reduction in their circulation, but enhances the axial dispersion of fluid in the reactor.