Wong Yu Ching, Dai Cheng, Xian Qingyue, Yan Zhaoxu, Zhang Ziyi, Wen Weijia
Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
Division of Emerging Interdisciplinary Areas, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
Sci Rep. 2023 Oct 19;13(1):17896. doi: 10.1038/s41598-023-44969-9.
Dean's flow and Dean's instability have always been important concepts in the inertial microfluidics. Curved channels are widely used for applications like mixing and sorting but are limited to Dean's flow only. This work first reports the Dean's instability flow in high aspect ratio channels on the deka-microns level for [Formula: see text]. A new channel geometry (the tortuous channel), which creates a rolled-up velocity profile, is presented and studied experimentally and numerically along with other three typical channel geometries at Dean's flow condition and Dean's instability condition. The tortuous channel generates a higher De environment at the same Re compared to the other channels and allows easier Dean's instability creation. We further demonstrate the use of multiple vortexes for mixing. The mixing efficiency is considered among different channel patterns and the tortuous channel outperforms the others. This work offers more understanding of the creation of Dean's instability at high aspect ratio channels and the effect of channel geometry on it. Ultimately, it demonstrates the potential for applications like mixing and cell sorting.
迪恩流和迪恩不稳定性一直是惯性微流体学中的重要概念。弯曲通道广泛应用于混合和分选等应用，但仅限于迪恩流。这项工作首次报道了在十微米级别的高纵横比通道中，对于[公式：见原文]的迪恩不稳定性流动。提出了一种新的通道几何形状（曲折通道），它能产生卷起的速度剖面，并在迪恩流条件和迪恩不稳定性条件下，与其他三种典型通道几何形状一起进行了实验和数值研究。与其他通道相比，曲折通道在相同雷诺数下能产生更高的德拜环境，并更容易产生迪恩不稳定性。我们进一步展示了利用多个涡旋进行混合。在不同通道模式中考虑了混合效率，曲折通道的表现优于其他通道。这项工作有助于更深入地理解高纵横比通道中迪恩不稳定性的产生以及通道几何形状对其的影响。最终，它展示了在混合和细胞分选等应用中的潜力。
