Performance analysis of combined zigzag and curved micromixers

In microfluidic devices, effective mixing is one of the determining factors. In these applications, since the fluid velocity and diffusive properties are low, proper mixing does not occur autonomously, using micromixers would be a viable solution. In this regard, the current study introduced four different micromixers, which are combinations of zigzag and curved channels, and was numerically examined. To get a reasonable mixing index and lower pressure drop, analysis is done on the mixing and hydraulic characteristics of these channels. Afterward, the optional channel is determined by comparing the outcomes obtained from the examined cases with each other and the ordinary zigzag one. When designing the channels, geometrical parameters such as the channel cross-sectional area, height, the number of zigzag-form structure and flow path length are considered the same for all cases. The occupied space of the presented cases is less than that of the ordinary zigzag counterpart to keep the path length constant and as the channel’s geometrical parameters alter. The numerical analysis, based on three-dimensional Navier–Stokes equations, is carried out for a steady-state condition. The findings indicate that the presented micromixers operate more properly than a common zigzag one when considering mixing index, pressure drop and occupied space. Among the introduced cases, Case 4 exhibits a superiority over the others since it causes the same pressure drop while occupying less space, resulting in a 20% higher mixing index.