اثر میدان مغناطیسی بر حرکت، تغییر شکل و زمان جدایش قطرات سیالات نیوتنی و غیرنیوتنی در میکروکانال جریان متمرکز

نوع مقاله : مقاله پژوهشی

نویسندگان

دپارتمان مهندسی مکانیک، دانشکده فنی و مهندسی، دانشگاه خوارزمی

چکیده

در مطالعه‌ی حاضر، تأثیر میدان مغناطیسی خارجی بر فرآیند تشکیل قطرات با اندازه و فرکانسی متفاوت و همچنین تأثیر خواص غیرنیوتنی بر مشخصات این قطرات، در یک میکروکانال جریان متمرکز به روش عددی بررسی شده و از طریق دو مدل غیرنیوتنی ویسکوز کاریو و توانی، وابستگی تنش با نرخ کرنش، مورد ارزیابی گرفته است. همچنین، تحلیل معادلات پیوستگی و مومنتوم جریان دوفازی، تراکم ناپذیر و غیردائم، با استفاده از روش حجم محدود و یک الگوریتم عددی بر اساس تکنیک کسر حجمی انجام گرفته است تا تأثیر عدد باند (0 تا 0/2) و اندیس توانی (0/3، 0/6 و 1/3) بر روی فرآیند تشکیل‌شدن قطرات، اندازه و زمان جدایش آن‌ها مورد ارزیابی قرار گیرد. نتایج بدست آمده نشان می‌دهند که میان سیال نیوتنی و سیالات غیرنیوتنی با مدل‌های مختلف، قطره‌ی کاریو در عدد باند 0/2 دارای بیشترین حجم، معادل حجم بی‌بعد 1/56 بوده و تأثیر میدان مغناطیسی بر فرآیند تشکیل و جدایش قطرات، بیش از تأثیر معادله‌ی ساختاری (مدل ویسکوزیته) است. همچنین، با افزایش قدرت میدان مغناطیسی، زمان جدایش قطرات بیشتر شده و قطراتی بزرگتر با فرکانس تولیدی کمتر، حاصل شده است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Effect of Magnetic Field on Motion, Deformation, and Separation Time of Newtonian and Non-Newtonian Droplets in a Flow‐Focusing Microchannel

نویسندگان [English]

  • sima mashafi
  • mostafa esmaeili
Department of Mechanical Engineering, Faculty of Engineering, Kharazmi University , Tehran, Iran
چکیده [English]

In the present study, the effect of external magnetic field on the process of droplet formation with different sizes and frequencies in a flow-focusing micro-channel is numerically studied. Moreover, the influence of non-Newtonian properties on the droplet formation characteristics is investigated using two non-Newtonian Carreau and power-law models. To solve the continuity and momentum equations for unsteady, two-phase, and incompressible flow, the finite volume method is employed. A numerical algorithm based on the volume-of-fluid technique is used to determine the effect of Bond number (0 to 0.2) and Power-law indices (0.3, 0.6, and 1.3) on the droplet formation process along with their size and separation time. To validate the numerical solution, the formation of Newtonian fluid droplets at different values of magnetic field strength is compared with the results of other studies and very good agreement was observed. The results of the numerical solution show that the Carreau fluid droplet in the Bond number of 0.2 has the highest volume, which is equivalent to the dimensionless volume of 1.56. Also, the process of droplet formation is more affected by the magnetic field than by the non-Newtonian model. Besides, with developing the field strength, droplet separation time increases and as a result, larger droplets with lower frequency will be formed.

کلیدواژه‌ها [English]

  • Microfluidic
  • Droplet formation
  • Magnetic field
  • Non-Newtonian fluid
  • Numerical simulation
[1] P. Garstecki, M.J. Fuerstman, H.A. Stone, G.M. Whitesides, Formation of droplets and bubbles in a microfluidic T-junction-scaling and mechanism of break-up, Lab Chip, 6(3) (2006) 437-446.
[2] C.-P. Lee, T.-S. Lan, M.-F. Lai, Fabrication of two-dimensional ferrofluid microdroplet lattices in a microfluidic channel, Journal of Applied Physics, 115(17) (2014) 17B5271-5273.
[3] J. Sivasamy, T.-N. Wong, N.-T. Nguyen, L.T.-H. Kao, An investigation on the mechanism of droplet formation in a microfluidic T-junction, Microfluidics and Nanofluidics, 11(1) (2011) 1-10.
[4] S. Bashir, J.M. Rees, W.B. Zimmerman, Investigation of pressure profile evolution during confined microdroplet formation using a two-phase level set method, International Journal of Multiphase Flow, 60 (2014) 40-49.
[5] S. Takeuchi, P. Garstecki, D.B. Weibel, G.M. Whitesides, An Axisymmetric Flow-Focusing Microfluidic Device, Advanced Materials, 17(8) (2005) 1067-1072.
[6] J. Liu, S.-H. Tan, Y.F. Yap, M.Y. Ng, N.-T. Nguyen, Numerical and experimental investigations of the formation process of ferrofluid droplets, Microfluidics and Nanofluidics, 11(2) (2011) 177-187.
[7] Y. Hong, F. Wang, Flow rate effect on droplet control in a co-flowing microfluidic device, Microfluidics and Nanofluidics, 3(3) (2006) 341-346.
[8] J. Lian, X. Luo, X. Huang, Y. Wang, Z. Xu, X. Ruan, Investigation of microfluidic co-flow effects on step emulsification: Interfacial tension and flow velocities, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 568 (2019) 381-390.
[9] Q. Hu, T. Jiang, H. Jiang, Numerical Simulation and Experimental Validation of Liquid Metal Droplet Formation in a Co-Flowing Capillary Microfluidic Device, Micromachines (Basel), 11(2:169) (2020) 1-14.
[10] P. Zhu, L. Wang, Passive and active droplet generation with microfluidics: a review, Lab Chip, 17(1) (2016) 34-75.
[11] F. Schönfeld, D. Rensink, Simulation of Droplet Generation by Mixing Nozzles, Chemical Engineering & Technology, 26(5) (2003) 585-591.
[12] L. Tian, M. Gao, L. Gui, A Microfluidic Chip for Liquid Metal Droplet Generation and Sorting, Micromachines, 8(2:39) (2017) 1-12.
[13] H. Babahosseini, T. Misteli, D.L. DeVoe, Microfluidic on-demand droplet generation, storage, retrieval, and merging for single-cell pairing, Lab Chip, 19(3) (2019) 493-502.
[14] N.R. Beer, K.A. Rose, I.M. Kennedy, Monodisperse droplet generation and rapid trapping for single molecule detection and reaction kinetics measurement, Lab Chip, 9(6) (2009) 841-844.
[15] F. Malloggi, S.A. Vanapalli, H. Gu, D. van den Ende, F. Mugele, Electrowetting-controlled droplet generation in a microfluidic flow-focusing device, Journal of Physics: Condensed Matter, 19(46) (2007) 1-7.
[16] H. Geng, J. Feng, L.M. Stabryla, S.K. Cho, Droplet manipulations by dielectrowetting: Creating, transporting, splitting, and merging, in:  2017 IEEE 30th International Conference on Micro Electro Mechanical Systems (MEMS), 2017, pp. 113-116.
[17] M.A. Maleki, M. Soltani, N. Kashaninejad, N.-T. Nguyen, Effects of magnetic nanoparticles on mixing in droplet-based microfluidics, Physics of Fluids, 31:032001(3) (2019) 1-16.
[18] S.M.S. Murshed, S.H. Tan, N.T. Nguyen, T.N. Wong, L. Yobas, Microdroplet formation of water and nanofluids in heat-induced microfluidic T-junction, Microfluidics and Nanofluidics, 6(2) (2008) 253-259.
[19] T.H. Ting, Y.F. Yap, N.-T. Nguyen, T.N. Wong, J.C.K. Chai, L. Yobas, Thermally mediated breakup of drops in microchannels, Applied Physics Letters, 89(23: 234101) (2006) 1-3.
[20] Y. Wu, T. Fu, Y. Ma, H.Z. Li, Ferrofluid droplet formation and breakup dynamics in a microfluidic flow-focusing device, Soft Matter, 9(41:9792) (2013) 1-7.
[21] C.N. Baroud, M.R. de Saint Vincent, J.P. Delville, An optical toolbox for total control of droplet microfluidics, Lab Chip, 7(8) (2007) 1029-1033.
[22] Y. Huang, Y.L. Wang, T.N. Wong, AC electric field controlled non-Newtonian filament thinning and droplet formation on the microscale, Lab Chip, 17(17) (2017) 2969-2981.
[23] M. Esmaeili, K. Sadeghy, MHD Flow of Power-Law Fluids in Locally-Constricted Channels, Nihon Reoroji Gakkaishi, 37(4) (2009) 181-189.
[24] M.J. Ghahderijani, M. Esmaeili, M. Afrand, A. Karimipour, Numerical simulation of MHD fluid flow inside constricted channels using lattice Boltzmann method, Journal of Applied Fluid Mechanics, 10(6) (2017) 1639-1648.
[25] M. Bayareh, An updated review on particle separation in passive microfluidic devices, Chemical Engineering and Processing - Process Intensification, 153 (2020) 107984-107918.
[26] S.-H. Tan, N.-T. Nguyen, L. Yobas, T.G. Kang, Formation and manipulation of ferrofluid droplets at a microfluidicT-junction, Journal of Micromechanics and Microengineering, 20(4:045004) (2010) 1-10.
[27] J. Liu, Y.F. Yap, N.-T. Nguyen, Numerical study of the formation process of ferrofluid droplets, Physics of Fluids, 23(7:072008) (2011) 1-10.
[28] Q. Yan, S. Xuan, X. Ruan, J. Wu, X. Gong, Magnetically controllable generation of ferrofluid droplets, Microfluidics and Nanofluidics, 19(6) (2015) 1377-1384.
[29] V.B. Varma, A. Ray, Z.M. Wang, Z.P. Wang, R.V. Ramanujan, Droplet Merging on a Lab-on-a-Chip Platform by Uniform Magnetic Fields, Sci Rep, 6:37671 (2016) 1-12.
[30] A. Ray, V.B. Varma, P.J. Jayaneel, N.M. Sudharsan, Z.P. Wang, R.V. Ramanujan, On demand manipulation of ferrofluid droplets by magnetic fields, Sensors and Actuators B: Chemical, 242 (2017) 760-768.
[31] A. Sequeira, J. Janela, An Overview of Some Mathematical Models of Blood Rheology, in: M.S. Pereira (Ed.) A Portrait of State-of-the-Art Research at the Technical University of Lisbon, Springer Netherlands, Dordrecht, 2007, pp. 65-87.
[32] E. Chiarello, A. Gupta, G. Mistura, M. Sbragaglia, M. Pierno, Droplet breakup driven by shear thinning solutions in a microfluidic T-junction, Physical Review Fluids, 2(12) (2017) 1-12.
[33] C.D. Xue, Z.P. Sun, Y.J. Li, K.R. Qin, Non-Newtonian Droplet Generation in a Flow-Focusing Microchannel, in:  ASME 2019 6th International Conference on Micro/Nanoscale Heat and Mass Transfer, 2019, pp. 1-7.
[34] L. Derzsi, M. Kasprzyk, J.P. Plog, P. Garstecki, Flow focusing with viscoelastic liquids, Physics of Fluids, 25(9) (2013) 1-18.
[35] A.J.T. Teo, M. Yan, J. Dong, H.-D. Xi, Y. Fu, S.H. Tan, N.-T. Nguyen, Controllable droplet generation at a microfluidic T-junction using AC electric field, Microfluidics and Nanofluidics, 24(3) (2020) 1-9.
[36] A. Khater, O. Abdelrehim, M. Mohammadi, M. Azarmanesh, M. Janmaleki, R. Salahandish, A. Mohamad, A. Sanati-Nezhad, Picoliter agar droplet breakup in microfluidics meets microbiology application: numerical and experimental approaches, Lab Chip, 20(12) (2020) 2175-2187.
[37] A. Taassob, M.K.D. Manshadi, A. Bordbar, R. Kamali, Monodisperse non-Newtonian micro-droplet generation in a co-flow device, Journal of the Brazilian Society of Mechanical Sciences and Engineering, 39(6) (2017) 2013-2021.
[38] V. Amiri Roodan, J. Gomez-Pastora, I.H. Karampelas, C. Gonzalez-Fernandez, E. Bringas, I. Ortiz, J.J. Chalmers, E.P. Furlani, M.T. Swihart, Formation and manipulation of ferrofluid droplets with magnetic fields in a microdevice: a numerical parametric study, Soft Matter, 16(41) (2020) 9506-9518.
[39] A. Fluent, Ansys Fluent Theory Guide, ANSYS Inc., USA,  (2013).
[40] S. Hund, M. Kameneva, J. Antaki, A Quasi-Mechanistic Mathematical Representation for Blood Viscosity, Fluids, 2(1) (2017) 1-17.