Numerical Simulation of Fluid Flow on Rotating Microchannels for Centrifugal Micromixer Applications

Abstract

This study investigated the fluid flow transport through rotating rectangular microchannels, starting from specific numerical models developed with the Finite Element Method (FEM) based Comsol Multiphysics software. Seven channel models were considered here, having hydraulic diameters Dh between 200 and 240 µm and aspect ratios AR between 2 and 0.67. The rotating microchannel model having Dh = 240 µm and AR = 0.67, with the lowest hydraulic resistance, presented at a rotating speed ω = 400 rad/s the highest ratio the between Coriolis and centrifugal forces (β = 2.88). The highest axial velocity values along almost the entire channel length and the highest proportion of 1.34 between the maximum wall shear rates along z-direction and y-direction at the channel outlet were also obtained for this model. So, with the compromise of a higher pressure drop than the models having AR = 0.8, 1 and 1.43 at lower Dh of 200 – 222 µm, this channel model with AR = 0.67 can represent a promising candidate for the future development of a microchannel array system inside on a lab-on-a-CD platform with optimal mixing performance.