Numerical Investigation of the Secondary Flow Effect of Lateral Structure of Micromixing Channel on Laminar Flow

Publication date: Available online 13 February 2020Source: Sensors and Actuators B: ChemicalAuthor(s): Huanhuan Shi, Yali Zhao, Zhengchun LiuAbstractMicromixing remains challenge for microfluidic applications. Stretching or folding of laminar flows by precise structure could improve micromixing but meanwhile increase the pressure drop and fabrication cost. The outward lateral structure on micromixing channel has been adopted as a mild way to promote micromixing at low Reynolds condition, which was especially suitable for micromixing of trace precious reagent at low flow rate. Herein, this paper presents the numerical investigation of secondary flow effect generated by lateral structure on laminar flows. The difference of velocity field distribution (Δvelocity) between the lateral structure and the main channel is the necessary condition for generation of Dean Vortex. Especially, when the velocity difference along the main channel (x direction) is small and the velocity difference perpendicular to the main channel (y direction) is large, the greatest secondary flow effect would be generated, the micromixing would be improved. The optimal secondary flow effect was obtained through adjusting the size of semicircular lateral structure. The mixing enhancement resulted from lateral structure only showed advantage at Re = 1-4. The semicircular lateral structure was respectively applied to T-shape, Zigzag and Spit and Recombine micromixers, respectively. Remarkable mixing enhancemen...
Source: Sensors and Actuators B: Chemical - Category: Chemistry Source Type: research