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.

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Jeong, G. S., Chung, S., Kim, C. B., and Lee, S. H., 2010, “Applications of Micromixing Technology,” Analyst, 135, pp. 460–473. [CrossRef] [PubMed]
Nguyen, N. T., and Wu, Z., 2005, “Micromixers-A Review,” J. Micromech. Microeng., 15, pp. R1–R16. [CrossRef]
Hessel, V., Löwe, H., and Schönfeld, F., 2005, “Micromixers-A Review on Passive and Active Mixing Principles,” Chem. Eng. Sci., 60, pp. 2479–2501. [CrossRef]
Aubin, J., Ferrando, M., and Jiricny, V., 2010, “Current Methods for Characterising Mixing and Flow in Microchannels,” Chem. Eng. Sci., 65, pp. 2065–2093. [CrossRef]
Elmabruk, A. M., Ye, M., Wang, Y., and Dai, Y., 2008, “A State-of-the-Art Review of Mixing in Microfluidic Mixers,” Chin. J. Chem. Eng., 16(4), pp. 503–516. [CrossRef]
Hsiung, S. K., Lee, C. H., Lin, J. L., and Lee, C. B., 2007, “Active Micro-Mixers Utilizing Moving Wall Structures Activated Pneumatically by Buried Side Chambers,” J. Micromech. Microeng., 17, pp. 129–138. [CrossRef]
Vilfan, M., Potočnik, A., Kavčič, B., Osterman, N., Poberaj, I., Vilfan, A., and Babič, D., 2010, “Self-Assembled Artificial Cilia,” Proc. Natl. Acad. Sci. U.S.A., 107(5), pp. 1844–1847. [CrossRef] [PubMed]
Affanni, A., and Chiorboli, G., 2010, “Development of an Enhanced MHD Micromixer Based on Axial Flow Modulation,” Sens. Actuators B, 147, pp. 748–754. [CrossRef]
Luong, T.-D., Phan, V.-N., and Nguyen, N.-T., 2011, “High-Throughput Micromixers Based on Acoustic Streaming Induced by Surface,” Microfluid. Nanofluid., 10, pp. 619–625. [CrossRef]
Jeon, W., and Shin, C. B., 2009, “Design and Simulation of Passive Mixing in Microfluidic Systems With Geometric Variations,” Chem. Eng. J., 152, pp. 575–582. [CrossRef]
Lin, Y. C., Chung, Y. C., and Wu, C. Y., 2007, “Mixing Enhancement of the Passive Microfluidic Mixer With J-Shaped Baffles in the Tee Channel,” Biomed. Microdevices, 9, pp. 215–221. [CrossRef] [PubMed]
Bhagat, A. A. S., Peterson, E. T. K., and Papautsky, I., 2007, “A Passive Planar Micromixer With Obstructions for Mixing at Low Reynolds Numbers,” J. Micromech. Microeng., 17, pp. 1017–1024. [CrossRef]
Hessel, V., Hardt, S., Löwe, H., and Schönfeld, F., 2003, “Laminar Mixing in Different Interdigital Micromixers: I. Experimental Characterization,” AIChE J., 49(3), pp. 566–577. [CrossRef]
Adeosun, J. T., and Lawal, A., 2009, “Numerical and Experimental Mixing Studies in a MEMs-based Multilaminated/Elongated Flow Micromixer,” Sens. Actuators B, 139, pp. 637–647. [CrossRef]
Xie, H., Fan, Y., and Yang, H., 2011, “New 3D SAR Micromixer Based on 2D Standard Photolithographic Technique,” Micro Nano Lett., 6(6), pp. 366–371. [CrossRef]
Li, L., Yang, C., Shi, H., Liao, W.-C., Huang, H., Lee, L. J., Castro, J. M., and Yi, A. Y., 2010, “Design and Fabrication of an Affordable Polymer Micromixer for Medical and Biomedical Applications,” Polym. Eng. Sci., 50(8), pp. 1594–1604. [CrossRef]
Stroock, A. D., Dertinger, S. K. W., Ajdari, A., Mezić, I., Stone, H. A., and Whitesides, G. M., 2002, “Chaotic Mixer for Microchannels,” Science, 295, pp. 647–651. [CrossRef] [PubMed]
Lynn, N. S., and Dandy, D. S., 2007, “Geometric Optimization of Helical Flow in Grooved Micromixers,” Lab Chip, 7(5), pp. 580–587. [CrossRef] [PubMed]
Du, Y., Zhang, Z., Yim, C. H., Lin, M., and Cao, X., 2010, “A Simplified Design of the Staggered Herringbone Micromixer for Practical Applications,” Biomicrofluidics, 4, p. 204105.
Somashekar, V., Olsen, M. G., and Stremler, M. A., 2009, “Flow Structure in a Wide Microchannel With Surface Grooves,” Mech. Res. Commun., 36, pp. 125–129. [CrossRef]
Schönfeld, F., and Hardt, S., 2004, “Simulation of Helical Flows in Microchannels,” AIChE J., 50(4), pp. 771–778. [CrossRef]
Wiggins, S., and Ottino, J. M., 2004, “Foundations of Chaotic Mixing,” Philos. Trans. R. Soc. London, Ser. A, 362, pp. 937–970. [CrossRef]
Aref, H., 1984, “Stirring by Chaotic Advection,” J. Fluid Mech., 143, pp. 1–21. [CrossRef]
Jiang, F., Drese, K. S., Hardt, S., Kupper, M., and Schonfeld, F., 2004, “Helical Flows and Chaotic Mixing in Curved Micro Channels,” AIChE J., 50(9), pp. 2297–2305. [CrossRef]
Tsai, R.-T., and Wu, C.-Y., 2011, “An Efficient Micromixer Based on Multidirectional Vortices Due to Baffles and Channel Curvature,” Biomicrofluidics, 5, p. 014103. [CrossRef]
Liu, R. H., Stremler, R. A., Sharp, K. V., Olsen, M. G., Santiago, J. G., Adrian, R. J., Aref, H., and Beebe, D. J., 2000, “Passive Mixing in a Three Dimensional Serpentine Microchannel,” J. Microelectromech. Syst., 9(2), pp. 190–197. [CrossRef]
Fan, Y. F., and Hassan, I., 2010, “Experimental and Numerical Investigation of a Scaled-Up Passive Micromixer Using Fluorescence Technique,” Exp. Fluids, 49, pp. 733–747. [CrossRef]
Xia, H. M., 2009, “Fluid Mixing Enhancement Through Chaotic Advection in Mini/Micro-Channel,” Ph.D. thesis, National University of Singapore, Singapore.
Hardt, S., and Schönfeld, F., 2003, “Laminar Mixing in Different Interdigital Micromixers: II. Numerical Simulations,” AIChE J., 49(3), pp. 578–584. [CrossRef]
Howell, P. B., Jr., Mott, D. R., Ligler, F. S., Golden, J. P., Kaplan, C. R., and Oran, E. S., 2008, “A Combinatorial Approach to Microfluidic Mixing,” J. Micromech. Microeng., 18, p. 115091. [CrossRef]
Ansari, M. A., Kim, K. Y., Anwar, K., and Kim, S. M., 2010, “A Novel Passive Micromixer Based on Unbalanced Splits and Collisions of Fluid Streams,” J. Micromech. Microeng., 20, p. 055007. [CrossRef]
Cook, K. J., Fan, Y. F., and Hassan, I. G., 2011, “Experimental Investigation of a Scaled-Up Passive Micromixer With Uneven Interdigital Inlet and Tear-Drop Obstruction Elements,” Exp. Fluids, 52(5), pp. 1261–1275. [CrossRef]
Lu, Z., McMahon, J., Mohamed, H., Barnard, D., Shaikh, T. R., Manella, C. A., Wagenknecht, T., and Lu, T. M., 2010, “Passive Microfluidic Device for Submillisecond Mixing,” Sens. Actuators B, 144, pp. 301–309. [CrossRef]
Fan, Y. F., 2009, “Experimental and Numerical Investigations of Novel Passive Micromixers Using μ-IF,” MASc. thesis, Concordia University, Montreal.


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Fig. 1

Test section depicting locations of measurement

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Fig. 3

Experimental facility used for flow visualization and induced fluorescence experiments

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Fig. 2

Dimensions of test section

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Fig. 4

Sample calibration curve depicting linear relationship between fluorescence concentration and intensity

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Fig. 5

Data processing procedure

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Fig. 9

Quantitative validation of numerical work at Re = 1 and 50

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Fig. 10

Flow visualization of entire test section at various Reynolds numbers

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Fig. 11

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

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Fig. 12

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

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Fig. 13

Concentration distribution at Re = 10 at L2

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Fig. 14

Concentration distribution at Re = 50 at L2

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Fig. 7

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

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Fig. 8

Qualitative validation of numerical work at Re = 50

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Fig. 6

Boundary conditions and grid system used for numerical simulation

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Fig. 15

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

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Fig. 16

Numerically and experimentally obtained mixing indices at the outlet

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Fig. 17

Mixing indices of various mixers at similar equivalent lengths




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