Numerical Study on a passive micromixer with sinusoidal channel walls

A. Afzal, K.-Y. Kim
Inha University, KR

Keywords: micromixer, numerical analysis, sinusoidal channel, mixing index

Summary:

Mixing of liquid samples in microfluidic systems has attracted many researchers mainly due to small characteristic dimensions of these channels, absence of turbulence and small diffusion coefficients. Depending on the mode of operation, different realizations of micromixers have been developed. In the present study, a passive micromixer with sinusoidal walls is proposed. With wavelength as the geometrical parameter, the proposed micromixer is investigated for a wide Reynolds number range 0.1 ≤ Re ≤ 50. Ethanol and water are used as the working fluids for mixing. A mixing index is employed to evaluate the performance of the micromixer. The mixing index is found to have a strong dependence on wavelength of the sinusoidal channel walls. For a fixed path length, enhanced mixing was observed due to reduction in diffusion distance (0.1 ≤ Re ≤ 1) and stronger Dean vortices (Re >10) as the wavelength is decreased. Due to simple in-plane structure, the proposed micromixer can easily be realized and integrated with microfluidic systems.