Vortex-induced vibration effects on mixing performance

The effect of vortex-induced vibration (VIV) of an elastically mounted rigid circular cylinder with two degrees of freedom movement on the mixing process in a straight channel micromixer is studied. The main objective is to investigate the effect of the reduced velocity ranging from 2 to 16 and the Peclet number in the range of 200-800 on the mixing index, pressure drop, mixing performance, streamwise and transverse displacements and oscillations frequencies. The mass-spring-damper system is utilized in order to model the cylinder vibration. The results indicate that the VIV improves the mixing efficiency significantly at low reduced velocities. In addition, the positive effect of VIV on mixing performance is greater at high Peclet numbers. In comparison with the stationary cylinder, at the reduced velocities of 2.5 and 4.5, an amazing improvement of 82.7% in the mixing index and 24% in the mixing performance is observed, respectively.