Numerical Study on a Passive Micromixer with Sinusoidal Channel Walls

A computational study is carried out for a passive micromixer with wavy channel walls of sinusoidal variation for Reynolds numbers in the range 0.1 <= Re <= 30. A mixing index is used to evaluate the performance of the micromixer. The mixing performance showed a strong dependence on the wavelength of the sinusoidal walls over the entire Re range considered. A shift in the center of rotation of Dean vortices toward inner sinusoidal wall for lower wavelength mixers was found to be an important factor significantly affecting the chaotic mechanism at higher Re. For a fixed mixing length, the sinusoidal design showed a remarkably improved mixing performance compared to a square-wave channel. This micromixer can easily be realized and integrated with microfluidic systems due to its simple in plane structure.