This paper investigates the path selection of bubbles suspended in different power-law carrier liquids in microfluidic channel networks. A finite volume-based numerical method is used to analyze the two-dimensional incompressible fluid flow in microchannels, while the volume of fluid method is used to capture the gas–liquid interface. To instill the influences of shear thinning, Newtonian, and shear-thickening fluids, the range of power-law indices (n) is varied from 0.3 to 1.5. We have validated our numerical model with the available literature data in good agreement. We have investigated the nonlinearity in the hydrodynamic resistance which arises due to single-phase non-Newtonian fluid flow. The path selection of a bubble in power-law fluids is examined from the perspective of velocity distribution and bubble deformation. We have found that the bubble indeed goes to the channel with a higher flow rate for all power-law fluids, but interestingly it did not always take the shorter route channel at a junction for n = 0.3. Our results suggest that long channels need not be more resistant for every fluid and that the longest arm becomes the least resistant resulting in the bubble leading into the long arm at a junction for shear-thinning fluid. We have proposed a deterministic model that enables predicting the second bubble path in a single bubble system for any location of the first bubble. We believe that the present study results will help design future generation microfluidic systems for efficient drug delivery and biomedical and biochemical applications.

中文翻译：

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通过幂律流体中的简单和级联微通道环路进行气泡传播的确定性模型

本文研究了微流体通道网络中悬浮在不同幂律载液中的气泡的路径选择。基于有限体积的数值方法用于分析微通道中二维不可压缩流体流动，而流体体积法用于捕获气液界面。为了灌输剪切稀化、牛顿流体和剪切稠化流体的影响，幂律指数的范围 ( n) 从 0.3 到 1.5 不等。我们已经验证了我们的数值模型与可用的文献数据非常吻合。我们已经研究了由单相非牛顿流体流动引起的流体动力阻力的非线性。从速度分布和气泡变形的角度研究了幂律流体中气泡的路径选择。我们发现对于所有幂律流体，气泡确实以更高的流速进入通道，但有趣的是，对于n  = 0.3. 我们的结果表明，长通道不需要对每种流体都具有更大的阻力，最长的臂变得阻力最小，导致气泡在剪切稀化流体的连接处通向长臂。我们提出了一个确定性模型，该模型能够针对第一个气泡的任何位置预测单个气泡系统中的第二个气泡路径。我们相信，目前的研究结果将有助于设计下一代微流体系统，以实现有效的药物输送以及生物医学和生化应用。