The present work describes the design principles of a two-stage trifurcation microchannel for focusing and separation of the particulate mixture with multisized particles from a solid–liquid mixture. A finite element method based numerical framework coupled with lagrangian point particle approach is used to investigate the migration dynamics of neutrally buoyant particles leading towards separation in microchannels. A detailed investigation has been carried out on the design of the separation branches to enhance the overall particle separation performance. Factors like opening width of the separatory branch (b_ci), branching angle (\(\alpha\)), and branching length ratio (\(\beta_{i}\)) are found to affect the momentum distribution at the branching zone that has an adverse effect on the separation of focused particles. The maximum and minimum limit on the particle size and second stage focusing channel length is defined based on the width and length corresponding to the first-stage channel. An improved model is proposed that incorporated the appropriate design changes to overcome the problem of nonseparation of particles due to restricted opening width in the second stage. The results suggest that the improved model can achieve 100% separation of a range of particle sizes in one pass. Further, it substantially reduces the footprint of the channel as compared to a single-stage design. This work will help in efficiently designing two-stage trifurcating microchannels for separating particulate matter from carrier fluid, and the same principles can also be extended in designing multistage linear microchannels for separation and sorting applications.

目前的工作描述了两级​​三叉微通道的设计原理，用于从固液混合物中聚焦和分离具有多尺寸颗粒的颗粒混合物。基于有限元方法的数值框架与拉格朗日点粒子方法相结合，用于研究导致微通道中分离的中性浮力粒子的迁移动力学。对分离分支的设计进行了详细研究，以提高整体颗粒分离性能。分枝的开口宽度 ( b _{c i} )、分枝角 ( \(\alpha\) ) 和分枝长度比 ( \(\beta_{i}\) 等因素) 会影响分支区的动量分布，这对聚焦粒子的分离有不利影响。粒度和第二级聚焦通道长度的最大和最小限制是根据第一级通道对应的宽度和长度来定义的。提出了一种改进的模型，该模型结合了适当的设计更改，以克服由于第二阶段开口宽度受限而无法分离颗粒的问题。结果表明，改进的模型可以在一次通过中实现一系列粒径的 100% 分离。此外，与单级设计相比，它大大减少了通道的占地面积。这项工作将有助于有效地设计用于从载液中分离颗粒物质的两级三叉微通道，