Numerical and experimental investigations of spiral and serpentine micromixers over a wide Reynolds number range

Micromixers are important components in microfluidic systems and play a pivotal role in chemical processes. In this work, numerical simulation and experimental studies were used to investigate the mixing efficiencies of spiral (S-M) and serpentine (C-S-M) micromixers in a wide Reynolds number (Re) range. We found that the structure of the Dean vortex played a crucial role in the mass transfer of the mixing process. The two structures produced Dean vortices with double vortex structures at the Re of 1 and 300, the mixing efficiency of C-S-M was lower than S-M. A Dean vortex with a four-vortex structure was produced in the two micromixers at the Re of 300 and 500, and the mixing efficiency of C-S-M was higher than S-M. Finally, the running cost (RC) concept was proposed to evaluate the comprehensive efficiencies of the two micromixers, which showed that the RC of S-M was lower at the Re of 50 and 100, and the RC of C-S-M was lower at the Re of 300 and 500. Our research may provide theoretical guidance for the design and application of micromixers.