Study of mixing in circular unbalanced split & recombine micromixer

In the present work, numerical simulation has been performed to analyze the mixing
of fluids inside a passive circular unbalanced split & recombine micromixer. The continuity,
Navier-Stokes & mass diffusion equations were solved and numerical simulation were
performed for aspect ratios of 3.00. The width ratio (w1/w2) was varied for seven different
values between 1.90 & 2.20 and numerical simulations were performed for five different
Reynolds numbers (10, 20, 40, 60 & 80) at each value of width ratio. The mixing phenomenon
was explained with the help of stream lines plots, contour plots etc. The generation of
secondary flows across the transverse plane and their contribution in achieving better mixing
has been explained. The mixing performance of the micromixer is quantified with the help of
mixing index.