PIV experiments and CFD simulations of liquid–liquid mixing in a planetary centrifugal mixer (PCM)

Abstract

A new type of blade-free mixer, the planetary centrifugal mixer (PCM), has recently attracted widespread interest. The aim of this study was to simulate the macromixing and micromixing characteristics of two miscible liquids in a PCM. Particle image velocimetry experiments were performed to validate the computational fluid dynamics model. The mixing index and the potential of diffusive mixing based on the intensity and scale of segregation were employed to accurately evaluate the mixing homogeneity. The results showed the remarkable mixing efficiency of the PCM; the mixing process was 95% completed in 10 s in most cases. Chaotic flows and vortices were observed in the PCM, which promoted mixing. After optimizing the design, the mixing time was reduced by 54%, and the extensional efficiency, velocity magnitude, and strain rate were increased by 38%, 35%, and 58%, respectively.