Numerical Investigation of Fluid Mixing in a Micro-Channel Mixer with Two Rotating Stirrers by Using the Incompressible SPH Method

Abstract

<em>Fluid mixing is a crucial and challenging process for microfluidic systems, which are widely used in biochemical processes. Because of their fast performance, active micromixers </em><em>that use stirrer blades are considered for biological applications. In the present study, by using a robust</em><em> and convenient Incompressible Smoothed Particle Hydrodynamics (ISPH) method, miscible mixing within a two-blade micromixer is investigated. The problem discussed herein is represented by </em><em>an active micromixer comprising two stir-bars that rotate to mix the fluids. Because of its Lagrangian</em><em> nature, Smoothed Particle Hydrodynamics is an appropriate and convenient method for simulating moving boundary problems and tracking the particles in the mixing process.</em> <em>Previous investigations have been carried out for mixing flow for a low Schmidt number. However, a low Schmidt number </em><em>is barely applicable for liquid mixing. Hence, in the present study, the Schmidt number is considered</em><em> to be Sc=1000. The present results show that the two-blade micro-channel mixer considerably improves the mixing rate in comparison with the one-blade micro-channel mixer.</em>