Numerical modeling of centrifugal microfluidic flow in rectangular channels for Lab-on-a-CD platform applications

A rectangular radial microchannel model having the same geometric dimensions as one type of microchannel placed on a PC-controlled centrifugal Disk: length e = 2.1 cm, height h = 65 μm and width Δy = 320 μm was considered here from an experimental work reported in literature. Fluid flow transport through this standard channel was numerically developed with the Finite Element Method (FEM) based Comsol Multiphysics software, simulation performed at rotating speeds ω between 25 and 300 rad/s. Other three rotating microchannel models with different aspect ratios AR have been simulated after by increasing the channel height from 65μm to 160 μm, 200 μm and 240 μm and by maintaining the same width of 320 μm. From the simulations of standard experimental type channel resulted that even at 300 rad/s, transverse Coriolis force was only close to half of centrifugal force, no secondary flow being induced in this case and a diffusion-based mixing is developed for this particular channel geometry. The radially rotating channel model was validated after comparing the FEM results with results from other two commercial finite volume codes (CFX and Fluent) reported in a numerical research study of a microchannel with e = 10 mm and Δy = h = 200 μm.