Mixing efficiency enhancement by a modified curved micromixer: A numerical study

The flow characteristics and mixing efficiency in a novel chaotic micromixer is numerically investigated from both eulerian and lagrangian viewpoints. The configuration consists of four successive quadrant units organized in a non-planar arrangement. A scalar equation is solved alongside conversation equations to determine the concentration of dye species. The effect of Reynolds number and aspect ratio on velocity field and streamlines, mixing index, pressure drop, mixing performance, energy efficiency factor and entropy generation are evaluated and some comparisons are made against a simple curved micromixer. The results reveal that the chaotic configuration is responsible for generating unsymmetrical transverse flows throughout the micomixer. The modified curved micromixer can enhance mixing index 0-2.04 times at the cost of increment of pressure drop by only 0-1.23 times in comparison with those values of simple curved micromixer. The existence of an optimum Reynolds number in maximizing the energy efficiency factor of chaotic micro configuration is established. The chaotic advection plays more important role on mixing efficiency in narrower configurations. Our simulated findings disclose that the present chaotic micromixer is more efficient in chemical applications, in which a rapid mixing is required in micro scale, compared to conventional T-type those.