Effect of Optical Rotor on Mixing in Y-shaped Microchannel Flow

Abstract

This paper analyses numerically the effect of optical rotor with N-paddle (N=3, 4, and 5) on mixing process of two fluids in Y-shaped channel flow by computational fluid dynamics (CFD). Streakline tracking simulation is employed to study dynamic mixing in the mixer. Mixing performance of the mixer is quantitatively measured by the dispersive and distributive mixing indices. The streaklines show that only a portion of one fluid can enter the rotor region where chaotic motion is observed. They also demonstrate that mixing is enhanced by high shear rate only in a portion of the perimeter area of the rotor. Consequently, mixing performance of the mixer is not dependent on number of paddle, but on the ratio of the tip paddle velocity of the rotor to the mean velocity in the mixer (kinetic parameter). Mixing is enhanced with increasing kinetic parameter. These are quantitatively confirmed by the two mixing indices.

Keywords

• microfluidics
• mixing
• micro-channel
• diffusion
• numerical simulation