Numerical simulation of the mixing performance of a novel SAR micromixer with hollow mixing chamber and diverse connecting channel

Abstract

A three-dimensional splitting and recombining micromixer featuring hollow mixing chambers and diverse connecting channel geometries was proposed to enhance mixing efficiency. The performance of three distinct micromixer variants was assessed by analyzing the mixing index, pressure drop, and mixing energy cost across Reynolds numbers (Re) ranging from 0.01 to 20. Results indicate that the micromixer with hook-shaped connecting channels (HACM-H) demonstrates superior mixing efficiency, achieving a mixing index exceeding 0.9 over short distances (5 mm) and greater than 0.99 when Re > 15. Investigation of the inner arc radius of the hook-shaped channel revealed its significant impact on pressure drop compared to the mixing index. Furthermore, the performance of the scaled-up HACM-H micromixer was evaluated, showing that the mixing index remains nearly constant at a given Re, while the square of the amplification factor was inversely proportional to pressure drop and directly proportional to mixing time.