Experimental Research on Mixing Efficiency of Magnetic Micromixer

Movement of aggregated chains in magnetic fluid was caused by the rotation of external magnetic field to break the laminar flow for resulting in the chaotic flow and improving the mixing efficiency of the fluid. The experiments were performed with varying strength of magnetic field, rotation frequency and flow rate using micro particle image velocimetry (micro-PIV) technique. The results show that there is no obvious effect of the external magnetic field on the mixing efficiency when the magnetic field is strong enough to rotate the aggregated chains. However, the rotation frequency influences the mixing efficiency greatly. A critical value of the rotation frequency was found, below and above which the mixing efficiency increases and decreases with increasing the rotation frequency, respectively. It is helpful to design the magnetic micro-mixer