The Effect of Fluid Viscosity in T-shaped Micromixers (original) (raw)

Effective mixing in small volumes is a crucial step in many chemical and biochemical processes, where microreactors are to ensure a fast homogenization of the reactants. Physically, liquid flows in microfluidic channels are characterized by low values of the Reynolds number and, in general, large values of the massive Peclet number. Accordingly, since general strategies of flow control in microfluidic devices should not depend on inertial effects, reduction of the mixing length requires that there must be transverse flow components. In this paper, three-dimensional numerical simulations were performed to study the flow dynamics and mixing characteristics of liquids flows inside T-shaped micromixers, when the two inlet fluids are either both water or water and ethanol. In particular we showed that, contrary to what one could think beforehand, the mixing efficiency of water-ethanol systems is lower than the corresponding water-water case. 2 SIMULATION TECHNIQUE 2.1 Governing Equations Consider two fluids converging into a T junction: the two inlet streams have at the same temperature, so that, as the heat of mixing has a negligible effect