Numerical Study of Mixing in Microchannels Enhanced by Vibrating Stirs
- Lei S.
- Qingfeng Xia
- Xiaochuan Yang
In this paper, mixing in microscale channels augmented by vibrating stirs is numerically studied. The micro-mixer comprises of several micro stirs (µ-stirs) placed in the microscale channel. Chaotic advection appears for the fact that the incoming flow interplays with the µ-stirs being transversely moving between two sidewalls. A two-dimensional numerical model is developed in a CFD solver FLUENT and particularly a species model is employed to exhibit the effect of mass transfer enhancement. The numerical results reveal that the degree of mixing (DoM) representing the mixing level are primarily determined by Strouhal number (St) and the dimensionless pulsation amplitude of the µ-stirs (A). It is observed that DoM increases with the increase of St and eventually levels off at about 0.8, as St > 0.9. In addition, DoM is proportional to A2. Moreover, chaotic advection is demonstrated by tracing artificial particles injected using a discrete particle model. (DPM)