90°转角微流道内导流板应用特性数值研究

Numerical study on application performances of deflector in 90-degree curved microchannel

改善转角微流道内流体的二次流特性对提高微流体传输的可靠性具有重要意义。针对90°转角矩形截面微流道,本文提出在微流道转角处增加导流板来实现该区域二次流的主动调节和控制。本文设计了圆弧型和弧—直组合型两种导流板结构,建立了五种不同结构微流道模型,开展了流场对称性和Dean涡分析,流体相对横向动能ksec和流道局部阻力系数ζ90°计算。结果表明,导流板结构能有效改善微流道转角区的流场对称性,加速Dean涡的消失,降低二次流强度,同时也会引起流体流动局部阻力系数有所增加。

Improving the secondary flow characteristics of fluids in microchannels at corners is of great significance for enhancing the reliability of microfluidic transport.In this paper,for the 90-degree corner rectangular section microchannel,a guide plate is proposed to be added at the corner of the microchannel to actively regulate and control the secondary flow in this area.This paper designs two types of guide plate structures:arc-shaped and arc-straight combination type,establishes five different structural microchannel models,and carries out analysis of flow field symmetry and dean vortices,as well as calculations of fluid relative transverse kinetic energy and local resistance coefficient of the channel.The results show that the guide plate structure can effectively improve the flow field symmetry in the corner area of the microchannel,accelerate the disappearance of Dean vortices,reduce the intensity of secondary flow,and also cause an increase in the local resistance coefficient of fluid flow.