Many micromixing applications require simple structured passive mixers rather than complex structured passive or expensive active mixers. However, mixing quality in a typical simple structured passive mixer remains poor. In the present work, simple T-type micromixer is modified with a circumferential in-step at the entry of inlet channels to generate velocity components oblique to the mainstream inlet flow. The performance of T and T–T mixers with and without circumferential in-step has been estimated for various Re (0 to 700). Results showed that inlet sample flow achieved velocity components of three-dimensional nature with circumferential in-step, leading to a momentous degree of intertwinement and entanglement of samples during the collision at the confluence of inlet channels. As a result, a remarkable improvement in mixing is obtained in the presence of in-step for sufficiently higher flow rates of Re above 100 by T-mixer and Re above 300 by T–T mixer. In particular, T-mixer offers better advantage with in-step compared to T–T mixer; marking an improvement for Re as low as 100 and above, as well as exhibiting shorter mixing lengths. Therefore, the present design of simple structured T-mixer with in-step at entry can be an effective device for various micromixing applications.

中文翻译：

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结构简单、高效的被动T型微混合器，入口处圆周步进

许多微混合应用需要结构简单的无源混频器，而不是结构复杂的无源或昂贵的有源混频器。然而，典型的简单结构的无源混频器的混频质量仍然很差。在目前的工作中，简单的 T 型微混合器在入口通道的入口处被修改为圆周步进，以产生与主流入口流倾斜的速度分量。T 和 T-T 混合器的性能有和没有圆周步进已经估计了各种Re（0 到 700）。结果表明，入口样品流实现了具有圆周同步步长的三维性质的速度分量，导致在入口通道汇合处碰撞过程中样品发生了很大程度的缠绕和纠缠。其结果是，在在步骤的存在下的足够高的流速得到的混合显着改善再通过T-混合器和高于100重新高于300通过T-T型混合器。特别是，T-mixer 与 T-T 混合器相比，在步进方面具有更好的优势；标志着Re的改进低至 100 及以上，并表现出更短的混合长度。因此，目前在入口处设计的简单结构的 T 型混合器可以成为各种微混合应用的有效装置。