0
Research Papers: Flows in Complex Systems

Mixing Evaluation of a Passive Scaled-Up Serpentine Micromixer With Slanted Grooves

[+] Author and Article Information
Ibrahim Hassan

e-mail: ibrahimh@alcor.concordia.ca
Department of Mechanical and Industrial Engineering,
Concordia University,
Montreal, QC H3G 2W1, Canada

1Corresponding author.

Contributed by the Fluids Engineering Division of ASME for publication in the JOURNAL OF FLUIDS ENGINEERING. Manuscript received April 8, 2012; final manuscript received April 3, 2013; published online June 3, 2013. Assoc. Editor: Michael G. Olsen.

J. Fluids Eng 135(8), 081102 (Jun 03, 2013) (12 pages) Paper No: FE-12-1180; doi: 10.1115/1.4024146 History: Received April 08, 2012; Revised April 03, 2013

A novel, passive, scaled-up micromixer based on fluid rotation is proposed and evaluated experimentally and numerically over Reynolds numbers ranging from 0.5 to 100. Flow visualization is employed to qualitatively assess flow patterns, while induced fluorescence is used to quantify species distribution at five locations along the channel length. Two individual fluids are supplied to the test section via a Y-inlet. The fluid enters a meandering channel with four semicircular portions, each of which is lined with nine slanted grooves at the bottom surface. The main mixing channel is 3 mm wide and 0.75 mm deep, with a total length of 155.8 mm. Numerical simulations confirm rotation at all investigated Reynolds numbers, and the strength of rotation increases with increasing Reynolds number. Grooves are employed to promote helical flow, while the serpentine channel structure results in the formation of Dean vortices at Re ≥ 50 (Dean number ≥ 18.25), where momentum has a more significant effect. A decreasing-increasing trend in the degree of mixing was noted, with an inflection point at Re = 5, marking the transition from diffusion dominance to advection dominance. The increase in interfacial surface area is credited with the improved mixing in the advection-dominant regime, while high residence time allowed for significant mass diffusion in the diffusion-dominant regime. Good mixing was achieved at both high and low Reynolds numbers, with a maximum mixing index of 0.90 at Re = 100.

Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Test section depicting locations of measurement

Grahic Jump Location
Fig. 2

Dimensions of test section

Grahic Jump Location
Fig. 3

Experimental facility used for flow visualization and induced fluorescence experiments

Grahic Jump Location
Fig. 4

Sample calibration curve depicting linear relationship between fluorescence concentration and intensity

Grahic Jump Location
Fig. 5

Data processing procedure

Grahic Jump Location
Fig. 6

Boundary conditions and grid system used for numerical simulation

Grahic Jump Location
Fig. 7

Grid independence performed at exit of first mixing element (L2). Re = 100.

Grahic Jump Location
Fig. 8

Qualitative validation of numerical work at Re = 50

Grahic Jump Location
Fig. 9

Quantitative validation of numerical work at Re = 1 and 50

Grahic Jump Location
Fig. 10

Flow visualization of entire test section at various Reynolds numbers

Grahic Jump Location
Fig. 11

Close up of grooves 2–8 in the first mixing element at Re = 100

Grahic Jump Location
Fig. 12

Channel cross-section concentration distribution and streamlines at C1 and C2 over 0.5 ≤ Re ≤ 100 (numerical results)

Grahic Jump Location
Fig. 13

Concentration distribution at Re = 10 at L2

Grahic Jump Location
Fig. 14

Concentration distribution at Re = 50 at L2

Grahic Jump Location
Fig. 15

Numerically obtained evolution of mixing index along channel length for 0.5 ≤ Re ≤ 100

Grahic Jump Location
Fig. 16

Numerically and experimentally obtained mixing indices at the outlet

Grahic Jump Location
Fig. 17

Mixing indices of various mixers at similar equivalent lengths

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In