High hydrodynamic and thermal mixing performances of efficient chaotic micromixers: A comparative study

Abstract

Efficient micromixers are largely used in different industrial applications. The mixing in laminar regime at low Reynolds numbers has a major significance in some processes. Exploiting the physical phenomenon of chaotic advection to improve the mixing efficiency is a well-established technique. This work consists in studying numerically the influence of the micromixers geometry on the hydrodynamic and thermal mixing performances using different configurations, which are respectively: TLCCM with an aspect ratio of l/W = 1, L-Shape, OH, and OX. All micromixer geometries have the same hydraulic diameter and an equivalent length. The numerical simulations were performed with low Reynolds numbers (0.2 – 70). Navier-Stokes equations were solved numerically using a commercial CFD software (ANSYS Fluent). Thus, the model adopted to characterize the mixing is the species transport model. To analyze the obtained results, the mass fraction contours, the velocity vectors and profiles, the temperature contours, the friction coefficient and the mixing energy cost were presented. The results show that the proposed micromixer has the best mixing performance with a mixing index that reaches to 0.99, and thermal mixing index more than 0.932 at very low Reynolds numbers, it also has the lowest mixing energy cost compared to that obtained in previous works.