Modeling active micromixers with multiple microstirrers using smoothed particle hydrodynamics

The smoothed particle hydrodynamics method is used to explore the eects of design parameters on the mixing eciency of two types of active micromixer. First, the complex ow eld and the mixing process of two separated uids in a square mixing chamber with nine symmetric microstirrers are simulated. The in uence of design parameters, such as the microstirrer rotation arrangement and the angular velocity of the microstirrer, on the mixing performance, is investigated. The mixing index parameter on ten control points is calculated and the average mixing index is compared for dierent cases. Simulations illustrate that the rotation arrangement of microstirrers is a key parameter in the mixing process. Then, a parametric study is performed for a horizontal and a Y-shaped active micromixer, where the in uence of length, angular velocity, rotation or oscillation movement of the microstirrer, inlet Reynolds number, and inlet stream angle is investigated. It is also illustrated that the inlet Reynolds number and the Struhal number are prominent parameters that aect the mixing eciency of this type of active micromixer.