Convergent–divergent micromixer coupled with pulsatile flow

An efficient mixing system for a microfluidic platform that uses periodic sinusoidal characteristics in space and time is proposed in this work. A convergent–divergent channel with sinusoidal walls (space-periodic) represented the most effective coupling with pulsatile (time-periodic) flow among the five tested geometries. The effects of sinusoidal pulsing on mixing performance in the convergent–divergent microchannel were examined using unsteady Navier–Stokes equations. The mixing performance was analyzed using the Reynolds and Strouhal numbers, and the ratio of pulsing amplitude to steady flow velocity. The micromixer shows interesting mixing behaviors with these parameters in terms of instantaneous mixing patterns as well as overall mixing performance. The micromixer with pulsing inputs achieved mixing index, 0.92 within two periods of the sinusoidal walls.