A novel micromixer with multimixing mechanisms for high mixing efficiency at low Reynolds number

Abstract

In this paper, we propose a novel passive micromixer structure for high mixing efficiency based on the combination of multimixing principles. With a special structure, our proposed micromixer can create vortices, transversal flows and chaotic advections to provide high mixing efficiency event at low Reynolds number. Moreover, two narrow slits at two ends of each mixing unit remarkably reduce pressure drop, making it easy to be built into micro-devices. We conduct intensive simulation to evaluate the performance of our proposed micromixer by numerically solving the governing Navier-Stokes equation and convection-diffusion equation using COMSOL Multiphysics package. The simulation results indicate that our proposed micromixer may achieve stable mixing efficiency of 80% or above for a wide Reynolds number range from 0.5 to 100. Especially, at Reynolds number (Re) > 30, mixing efficiency is less dependent on Reynolds number. The mixing efficiency of our micromixer is two times higher than mixing efficiency of micromixer based on unbalanced splits and collisions of fluid at the same mixing channel length of 5mm. At Re = 30, our proposed micromixer has high mixing efficiency of 85% with moderate pressure drop ∆P = 12,600Pa.

A Review on Micromixers

“…Simulation results showed that it retained a high mixing efficiency of over 80% for a low Reynolds number of between 0.5 and 60 with a total mixing length of 3870 μm. Combining this micromixer with the unbalanced splits and cross-collisions of fluids, an improved micromixer with shifted trapezoidal chambers and a total mixing length of 5000 μm was then presented and shown in Figure 18 a [ 109 ]. Simulation results showed that the mixing efficiency was over 80% for an entire range of Reynolds numbers from 0.5 to 100.…”

Enhanced Fluid Mixing Using a Reversed Multistage Tesla Micromixer

“…Nguyen et al 21 found that the 3D Tesla structure works well at a Reynolds number ( Re ) > 5 for solution mixing. Re > 100 is uncommon in passive micromixers due to the limited pumping capacity to achieve a high Reynolds number 22–26. However, in this study, the upper limit of Re = 140 was chosen rather than 100 to observe anomalies.…”

Passive Micromixers

“…Simulation results showed that it retained a high mixing efficiency of over 80% for a low Reynolds number of between 0.5 and 60 with a total mixing length of 3870 µm. Combining this micromixer with the unbalanced splits and cross-collisions of fluids, an improved micromixer with shifted trapezoidal chambers and a total mixing length of 5000 µm was then presented and shown in Figure 18a [109]. Simulation results showed that the mixing efficiency was over 80% for an entire range of Reynolds numbers from 0.5 to 100.…”