Multidirectional vortices mixing in three-stream micromixers with two inlets

Abstract

In this work, we design, fabricate and compare three types of three-stream curved-straight-curved (CSC) micromixers, including the full three-stream (FTS) CSC micromixer, the CSC microchannel with internal side-wall injection and the CSC microchannel with external sidewall injection. In the three-stream CSC micromixers, there is a core stream sandwiched by two cladding streams into the CSC channel with baffles from two inlets. The sandwiched structure of streams and the multidirectional vortices due to flow separation and channel curvature contribute together to enhance mixing. We examine fluid mixing in the proposed micromixers by numerical simulation and using confocal spectral microscope imaging system. The present results show that the mixing efficiency increases without increasing the pressure applied much by the channel structure forming the sandwiched structure of streams. Besides, it is found that the FTS CSC micromixer is the preferable one among the micromixers considered.

The effect of chaotic advection on mixing degree and pressure drop of non-Newtonian fluids flow in curved micromixers

“…As the Reynolds number increases, the strength of secondary flows increases and mixing index becomes greater. Similar trends were reported by several researchers for Newtonian fluids [5,20,30] and by Afzal and Kim [1] for Carreau-Yasuda model of non-Newtonian fluids. In addition, by decreasing the power-law index and consequently increasing of apparent viscosity, the chaotic advection effect is weakened by viscous forces and as a result the degree of mixing decreases.…”

Enhancement of Mixing Performance of Non-Newtonian Fluids using Curving and Grooving of Microchannels

“…They observed that the mixing efficiency improved due to the multidirectional vortices. In another study, Tsai and Wu examined three curved-straight-curved (CSC) micromixers, which had three inlets (Tsai and Wu 2012). They studied three different configurations for inlets and obtained the mixing efficiency and pressure loss between channel inlets and outlet for all cases and introduced the best configuration.…”