Performance Evaluation Of H-shaped Micromixer

Abstract

Compared to conventional macroscopic methods, microfluidic devices have the advantages of reduced solvent, reagent and cell consumption, shorter reaction times, portability, low cost and low power consumption. This study propose two novel generation of three Dimensional splitting and recombination passive micromixers (the longitudinal and cross-sectional unbalanced micromixer) that are designed based on the H-shaped balanced micromixer geometry. Numerical simulation were performed to study the mixing dynamics of two miscible liquids(water & ethanol) in all three types of micromixers and results compared with the previous well-known H-shaped balanced micromixer. Laminar flow regime, incompressible, steady and no-slip velocity are Assumptions that govern fluid flow. It was found that mixing index and pressure drop are significantly affected by the unbalancing and depends on Reynolds number (inlet velocities). increasing the Reynolds number will increase mixing index, at Re=100 the mixing index of the cross-sectional unbalanced micromixer is more than 90% while at Re=20 this is less than 70%. Creating an unbalanced flow will increase mixing index, however, cross-sectional unbalancing is more effective than longitudinal unbalancing, at Re=100 the mixing index of the cross-sectional unbalanced micromixer has increased about 30% compared to the H-shaped balanced micromixer. Numerical results show that increasing the Reynolds number will increase pressure drop of all three types of micromixers. Compared with each other, the longitudinal unbalanced micro mixer and the H-shaped balanced micromixer with equal pressure drop, have 25% lower pressure drop than the cross-sectional unbalanced micromixer.