Numerical investigation of design of a passive micromixer compound shape on split and recombination concept

Abstract

Microchannels are a key component of these devices, and micromixers are the heart of these channels. The related study aims to produce micromixers with high efficiency with a simple shape. This work presents the design and numerical performance analysis of the flow using Computational Fluid Dynamics (CFD). This work is based on the SAR (Split and Recombination) concept with a zigzag shape. The mixing was investigated over a wide range of Re numbers (1-100). Four factors with three levels were optimized by the Taguchi method to achieve the optimal shape: angle, several periods, the ratio between width to diameter, width, and depth. The index of mixing is evaluated and focused on the variance of the fraction of the mass in the mixture. As a result, the index of mixing is enhanced with varied Reynolds numbers. The mixer with a 70°, 4-period (w/d = 0.125) and (w/t = 1) design was the optimal choice.

Keywords

• Computational Fluid Dynamics
• Mixing Index
• Passive Micromixer
• Spilt and recombination
• Optimization

Pasif mikro karıştırıcı için zikzak şeklinde bölme ve rekombinasyon kavramını içeren tasarımın sayısal olarak incelenmesi

Öz

Mikro kanallar cihazların bir parçasıdır ve mikro karıştırıcılar kanalların kalbidir denilebilir. İlgili çalışma, akışın tasarımını ve performans analizini Hesaplamalı Akışkanlar Dinamiği (HAD) ile sayısal olarak açıklamaktadır. Bu çalışma, zikzak şekilli SAR konseptine dayanmaktadır. Karıştırma, geniş bir Re sayısı aralığında (1-100) incelenmiştir. En uygun şekli elde etmek için üç seviyeli dört faktör Taguchi yöntemi ile optimize edilmiştir; açı, periyot, genişlik ile çap arasındaki oran arasındaki ilişki için de genişlik ve derinlik incelenmiştir. Karıştırma indeksi, karışımdaki kütle kesrinin varyansına odaklanarak değerlendirilmektedir. Sonuç olarak, karıştırma indeksi değişen Reynolds sayılarıyla arttığı görülmüştür. Karıştırıcıdaki en iyi tasarım 70o, 4-periyotlu, (w/d = 0.125) ve (w/t = 1) koşullarında elde edilmiştir.

Anahtar Kelimeler

• Hesaplamalı akışkanlar dinamiği (HAD)
• Karıştırma İndeksi
• Pasif Mikromikser
• Bölünme ve Rekombinasyon
• Optimizasyon

References

1. [1] Stone H. A., Stroock A. D., Ajdari, A. “Engineering flows in small devices microfluidics toward a lab-on-a-chip”. Annu. Rev. Fluid Mech., 36, 381-411, 2004.
2. [2] Whitesides, G. M. “The origins and the future microfluidics”. Nature, 442(7101), 368-373, 2006.
3. [3] Erickson D. “Towards numerical prototyping of labs-on-chip: modeling for integrated microfluidic devices”. J. Microfluid. Nanofluid, 1(4), 301-318, 2005.
4. [4] Damljanovic V., Christoffer Lagerholm B., Jacobson K. “Bulk and micropatterned conjugation of extracellular matrix proteins to characterized polyacrylamide substrates for cell mechanotransduction assays”, BioTechniques, 39(6), 847-851, 2005.
5. [5] Roumanie M., Delattre C., Mittler F., Marchand G., Meille, V., de Bellefon C., Pouteau P. “Enhancing surface activity in silicon microreactors: Use of black silicon and alumina as catalyst supports for chemical and biological applications”, Chem. Eng. J, 135, 317-326, 2008.
6. [6] Singh M. K., Anderson P. D., Meijer H. E. “Understanding and optimizing the SMX static mixer”, Macromol. Rapid Commun, 30(4‐5), 362-376, 2009.
7. [7] Tromeur M., Mahé C., Schwesinger N., Tranchant J. F. “Micromixers to produce cosmetic emulsions”, Int. J. Cosmet. Sci., 25(1‐2), 1-4, 2003.
8. [8] Stefanidis G. D., Vlachos D. G.” High vs. low temperature reforming for hydrogen production via microtechnology”, Chem. Eng. Sci, 64(23), 4856-4865, 2009.

9. [9] Liu Y., Deng Y., Zhang P., Liu Z., Wu Y. “Experimental investigation of passive micromixers conceptual design using the layout optimization method”, J. Micromech. Microeng, 23(7), 075002, 2013.
10. [10] Lin H., Storey B. D., Oddy M. H., Chen C. H., Santiago J. G. “Instability of electrokinetic microchannel flows with conductivity gradients”, Phys.Fluids, 16(6), 1922-1935, 2004.
11. [11] Capretto L., Cheng W., Hill M., Zhang X. “Micromixing within microfluidic devices”, Top. Curr. Chem, 27-68, 2011.
12. [12] Niu X., Lee Y. K. “Efficient spatial-temporal chaotic mixing in microchannels”, Chem. Eng. Sci., 13(3), 454, 2003.
13. [13] Himstedt H. H., Yang Q., Prasad Dasi L., Qian X., “S. Wickramasinghe”, R.; Ulbricht, M. Langmuir, 27, 5574-5581, 2011.
14. [14] Wei Z. H., Le, C. P. “Magnetic fluid micromixer with tapered magnets”, J. Appl. Phys., 105(7), 07B523, 2009.
15. [15] Granados-Ortiz F., Garcia-Cardosa M., Ortega-Casanova J. “Effect of wall modifications in a vortex shedding-based mechanical micromixer for heat/mass exchange”, European Journal of Mechanics - B/Fluids, 92, 174-190, 2022.
16. [16] Hossain, S., Lee, I., Kim, S. M., & Kim, K. Y. “A micromixer with two-layer serpentine crossing channels having excellent mixing performance at low Reynolds numbers”, Chem. Eng. J., 327, 268-277, 2017.
17. [17] Chen X., Zhao, Z. “Numerical investigation on layout optimization of obstacles in a three-dimensional passive micromixer”, Anal.Chim. Acta, 964,142-149, 2017.
18. [18] Chen, X., Li, T., Zeng, H., Hu, Z., & Fu, B. “Numerical and experimental investigation on micromixers with serpentine microchannels”, Int. J. of Heat and Mass Trans., 98, 131-140, 2016.
19. [19] Viktorov, V., Mahmud, M. R., & Visconte, C., “Design and characterization of a new HC passive micromixer up to Reynolds number 100”, Chem. Eng. Res. Des, 108, 152-163, 2016.
20. [20] Ruijin, W., Beiqi, L., Dongdong, S., & Zefei, Z. “Investigation on the splitting-merging passive micromixer based on Baker's transformation”, Sen. and Act. B: Chem., 249, 395-404., 2017.
21. [21] Raza, W., Hossain, S., & Kim, K. Y. “Effective mixing in a short serpentine split-and-recombination micromixer”, Sen. and Act. B: Chem., 258, 381-392, 2018.
22. [22] Gidde, R. R., Pawar, P. M., Ronge, B. P., Shinde, A. B., Misal, N. D., & Wangikar, S. S. “Flow field analysis of a passive wavy micromixer with CSAR and ESAR elements”. Micro. Tech., 25(3), 1017-1030.2019.
23. [23] Shah I., Kim S. W., Kim K., Doh Y. H., Choi, K. H. “Experimental and numerical analysis of Y-shaped split and recombination micro-mixer with different mixing units”, Chem. Eng. J, 358, 691-706, 2019.
24. [24] ttar, H., Zekry, R. S., Sharfo, S. M., Deif, M. A., Hafez, M., & Solyman. “Evaluation of The Mixing Performance in a Planar Passive Micromixer with T Micromixer with Square Chamber Mixing Units (SAR) ”. In 2023 2nd Inter. Eng. Conf.e on Elec.l, Energy, and Art. Intell. (EICEEAI) (pp. 1-7). IEEE.2023
25. [25] Lotfiani, A., & Rezazadeh, G. “A new two-layer passive micromixer design based on SAR-vortex principles”. Inter. J. of Chem. React. Eng., 19(3), 309-329. 2021
26. [26] Li, D., Hou, X., He, Y., & Wu, K. J. “Numerical simulation of the mixing performance of a novel SAR micromixer with hollow mixing chamber and diverse connecting channel”. Chem. Eng. and Processing-Process Intensification, 212, 110282. 2025.
27. [27] Celik I. B., Ghia U., Roache P. J., Freitas, C. J. “Procedure for estimation and reporting of uncertainty due to discretization in CFD applications”, J. Fluids Eng., 130(7), 2006.
28. [28] Ali M. S. M., Doolan C. J., Wheatley V. “Grid convergence study for a two-dimensional simulation of flow around a square cylinder at a low Reynolds number”, 7th Int. Conf. CFD in The Minerals and Process Industries, 1-6 , 2009.
29. [29] Verzicco, R., Pirozzoli, S., Leonardi, S. “Vortical Structures and Wall Turbulence”, European Journal of Mechanics - B/Fluids, 55, 241, 10.1016/j.euromechflu.2015.11.010, 2016.