Flow field analysis of a passive wavy micromixer with CSAR and ESAR elements

Abstract

The performance analysis of wavy micromixers with split and recombine (SAR) elements has been carried out. The two types of SAR elements viz. circular split and recombine elements and elliptical split and recombine elements are used to get benefit of SAR mechanism. The main concept in the proposed design is to enhance the interfacial area between the two fluids by creating a transverse flow and split and recombination of fluid flow streams with the help of SAR elements. The effects of balanced split and unbalanced split of SAR elements and operational parameter Reynolds number on the mixing index and pressure drop are evaluated. The COMSOL Multiphysics 5.0 is used for computational fluid dynamics analysis of micromixers. The analysis is carried out for balanced and unbalanced split of the mixing elements at various Reynolds numbers in the range of 0.1–75. The computation interfacial patterns on the planes perpendicular to the direction of fluid flow, mixing index and pressure drop are studied in depth. The results indicate that at inlet Reynolds number below 5, the mixing performance is diffusion dominated. However at Reynolds number greater than 5, the mixing index increases intensely due secondary flow and separation vortices, as well as SAR effect.