在过去的几十年中,具有弯曲几何形状的微通道已经用于微流体装置中的许多应用。在这样的几何形状中产生的迪安涡流已经使用不同的方法来控制,以增强设备在诸如混合、混合等应用中的性能。液滴分选,和颗粒/细胞分离。了解操纵方法对不同几何形状的迪安涡流的影响可以提供设计高效微流体装置中使用的关键信息。在这次审查中,总结了迪恩涡旋的物理特性和影响参数。收集并表示各种Dean数计算方法,以最大程度地减少由于缺少Dean无量纲数的统一定义公式而导致的对已发布信息的误解。因此,在参考文献中报告的所有Dean数值被重新计算为最常见的方法,以促进对现象的理解。根据从先前的数值和实验研究中收集的转换信息,得出的结论是,通道的长度和通道路径,例如,螺旋,蛇纹石,或者螺旋,也会影响流量状态。这篇综述还对其他几何参数的影响进行了详细的总结,例如横截面形状,纵横比,和曲率半径,关于迪恩漩涡的数量和排列。最后,考虑到液滴微流体的重要性,弯曲的几何形状对形状的影响,轨迹,以及通过弯曲通道的液滴的内部流动组织已经被审查。
Microchannels with curved geometries have been employed for many applications in microfluidic devices in the past decades. The Dean vortices generated in such geometries have been manipulated using different methods to enhance the performance of devices in applications such as mixing, droplet sorting, and particle/cell separation. Understanding the effect of the manipulation method on the Dean vortices in different geometries can provide crucial information to be employed in designing high-efficiency microfluidic devices. In this review, the physics of Dean vortices and the affecting parameters are summarized. Various Dean number calculation methods are collected and represented to minimize the misinterpretation of published information due to the lack of a unified defining formula for the Dean dimensionless number. Consequently, all Dean number values reported in the references are recalculated to the most common method to facilitate comprehension of the phenomena. Based on the converted information gathered from previous numerical and experimental studies, it is concluded that the length of the channel and the channel pathline, e.g., spiral, serpentine, or helix, also affect the flow state. This review also provides a detailed summery on the effect of other geometric parameters, such as cross-section shape, aspect ratio, and radius of curvature, on the Dean vortices\' number and arrangement. Finally, considering the importance of droplet microfluidics, the effect of curved geometry on the shape, trajectory, and internal flow organization of the droplets passing through a curved channel has been reviewed.