Analysis of Passive Mixing in a Serpentine Microchannel with Sinusoidal Side Walls

Abstract

Sample mixing is difficult in microfluidic devices because of laminar flow. Micromixers are designed to ensure the optimal use of miniaturized devices. The present study aims to design a chaotic-advection-based passive micromixer with enhanced mixing efficiency. A serpentine-shaped microchannel with sinusoidal side walls was designed, and three cases, with amplitude to wavelength (A/λ) ratios of 0.1, 0.15, and 0.2 were investigated. Numerical simulations were conducted using the Navier–Stokes equations, to determine the flow field. The flow was then coupled with the convection–diffusion equation to obtain the species concentration distribution. The mixing performance of sinusoidal walled channels was compared with that of a simple serpentine channel for Reynolds numbers ranging from 0.1 to 50. Secondary flows were observed at high Reynolds numbers that mixed the fluid streams. These flows were dominant in the proposed sinusoidal walled channels, thereby showing better mixing performance than the simple serpentine channel at similar or less mixing cost. Higher mixing efficiency was obtained by increasing the A/λ ratio.

Two-Way Coupling Fluid-Structure Interaction (FSI) Approach to Inertial Focusing Dynamics under Dean Flow Patterns in Asymmetric Serpentines

“…Dean patterns are commonly represented as flow field projections in a section of a microfluidic channel [26,34,45,46]. Such representation is indirectly based on the assumption that the streamlines of a hypothetical creeping flow are perpendicular to the said plane because its tangent components are taken as the Dean flow components.…”

Two-Way Coupling FSI Approach to Inertial Focusing Dynamics Under Dean Flow Patterns in Asymmetric Serpentines

“…Dean patterns are commonly represented as flow field projections in a section of a microfluidic channel [26,34,39,40]. Such representation is indirectly based on the assumption that the streamlines of an hypothetical creeping flow are perpendicular to said plane (the tangent components to the plane are taken as the Dean flow components).…”

Editorial for the Special Issue on Passive Micromixers

“…The important areas being focused upon are the numerical and experimental analyses of flow and mixing in different micromixers [1,2,3,4,5], optimization [6,7,8], and fabrication of micromixers [9]. In the review paper [10], recent developments in both active and passive micromixers are summarized and discussed.…”

“…Computational fluid dynamics (CFD) analysis of flow and mixing is seen as an important tool in designing passive micromixers in eight research articles [1,2,3,4,5,6,7,8]. Javaid et al [1] proposed a serpentine-shaped micromixer with sinusoidal walls and conducted a CFD analysis using COMSOL Multiphysics software.…”

“…Javaid et al [1] proposed a serpentine-shaped micromixer with sinusoidal walls and conducted a CFD analysis using COMSOL Multiphysics software. The numerical results showed a good agreement with a previously published experiment, with improved mixing performance compared to a simple serpentine channel.…”