An unrecognized inertial force induced by flow curvature in microfluidics
An unrecognized inertial force induced by flow curvature in microfluidics
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DOI：
10.1073/pnas.2103822118
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发表时间：
2021-07-20
影响因子：
11.1
通讯作者：
Hilgenfeldt, Sascha
中科院分区：
文献类型：
--
作者：
Agarwal, Siddhansh;Chan, Fan Kiat;Hilgenfeldt, Sascha
现代惯性微流体常规地采用围绕局部固体特征或微泡的振荡流，用于颗粒、液滴和细胞的受控的、特定的操纵。结果表明，惯性效应的理论，已经是最先进的几十年错过了主要的贡献，并大大低估了在一系列实际相关的条件下对小悬浮物体的力。提出了一种分析方法，推导出一套完整的惯性力，并将其量化为易于使用的运动方程的封闭形式，跨越从粘性到无粘流的整个范围。该理论预测了对振荡边界的额外吸引力贡献，即使是密度匹配的粒子，这是以前无法解释的实验观察。理论的准确性证明对全尺寸，三维直接数值模拟在其范围内。
Modern inertial microfluidics routinely employs oscillatory flows around localized solid features or microbubbles for controlled, specific manipulation of particles, droplets, and cells. It is shown that theories of inertial effects that have been state of the art for decades miss major contributions and strongly underestimate forces on small suspended objects in a range of practically relevant conditions. An analytical approach is presented that derives a complete set of inertial forces and quantifies them in closed form as easy-to-use equations of motion, spanning the entire range from viscous to inviscid flows. The theory predicts additional attractive contributions toward oscillating boundaries, even for density-matched particles, a previously unexplained experimental observation. The accuracy of the theory is demonstrated against full-scale, three-dimensional direct numerical simulations throughout its range.