Simulation of the mixing process in a straight tube with sudden changed cross-section

doi:10.1016/j.cjche.2016.01.011

摘要/Abstract

摘要： In this work,we revised the expression ofmixing intensity to describe the mixing output through a cross section in a flow system by considering heterogeneity of flow field, and carefully investigated the mixing process along a straight tube with expanding/contracting cross section by simulation method. The simulation results show that a sudden expansion of cross section has remarkable mixing intensification effect within a limited period (on the sub-second scale) or tube-length (on the millimeter scale), corresponding to the generation of considerable local vortices determined by both the flow capacity and the ratio of cross section change; a sudden contraction of cross section has instantaneous but weak mixing intensification effect; through introducing a local expansion structure with proper length, as the combination of sudden expansion and sudden contraction, their mixing intensification effects could be superposed. Besides, the rationality and importance are experimentally verified to explore the time profile of mixing intensity and carry out the vortex analysis by simulation for enhancing the selectivity of a complicated reaction system. These progresses may lead to more meaningful quantitative description of mixing process in a flow microreactor for some specific chemical processes.

关键词: Mixing, Intensification, Simulation, Sudden change in cross-section, Vortex

Abstract: In this work,we revised the expression ofmixing intensity to describe the mixing output through a cross section in a flow system by considering heterogeneity of flow field, and carefully investigated the mixing process along a straight tube with expanding/contracting cross section by simulation method. The simulation results show that a sudden expansion of cross section has remarkable mixing intensification effect within a limited period (on the sub-second scale) or tube-length (on the millimeter scale), corresponding to the generation of considerable local vortices determined by both the flow capacity and the ratio of cross section change; a sudden contraction of cross section has instantaneous but weak mixing intensification effect; through introducing a local expansion structure with proper length, as the combination of sudden expansion and sudden contraction, their mixing intensification effects could be superposed. Besides, the rationality and importance are experimentally verified to explore the time profile of mixing intensity and carry out the vortex analysis by simulation for enhancing the selectivity of a complicated reaction system. These progresses may lead to more meaningful quantitative description of mixing process in a flow microreactor for some specific chemical processes.

Key words: Mixing, Intensification, Simulation, Sudden change in cross-section, Vortex

Yangcheng Lü, Shan Zhu, Kai Wang, Guangsheng Luo. Simulation of the mixing process in a straight tube with sudden changed cross-section[J]. Chinese Journal of Chemical Engineering, 2016, 24(6): 711-718.

Yangcheng Lü, Shan Zhu, Kai Wang, Guangsheng Luo. Simulation of the mixing process in a straight tube with sudden changed cross-section[J]. Chin.J.Chem.Eng., 2016, 24(6): 711-718.

参考文献

[1] S.B. Cheng, C.D. Skinner, J. Taylor, S. Attiya, W.E. Lee, G. Picelli, D.J. Harrison, Development of a multichannel microfluidic analysis system employing affinity capillary electrophoresis for immunoassay, Anal. Chem. 73(2001) 1472-1479.

[2] J. Khandurina, T.E. McKnight, S.C. Jacobson, L.C.Waters, R.S. Foote, J.M. Ramsey, Integrated system for rapid PCR-based DNA analysis in microfluidic devices, Anal. Chem. 72(2000) 2995-3000.

[3] Y. Shi, P.C. Simpson, J.R. Scherer, D.Wexler, C. Skibola, M.T. Smith, R.A. Mathies, Radial capillary array electrophoresis microplate and scanner for high-performance nucleic acid analysis, Anal. Chem. 71(1999) 5354-5361.

[4] J. Rossier, F. Reymond, P.E. Michel, Polymer microfluidic chips for electrochemical and biochemical analyses, Electrophoresis 23(2002) 858-867.

[5] B. Ahmed-Omer, J.C. Brandt, T.Wirth, Advanced organic synthesis usingmicroreactor technology, Org. Biomol. Chem. 5(2007) 733-740.

[6] A.P. Harvey, M.R. Mackley, T. Seliger, Process intensification of biodiesel production using a continuous oscillatory flow reactor, J. Chem. Technol. Biotechnol. 78(2003) 338-341.

[7] N.T. Nguyen, S.T. Wereley, Fundamentals and applications of microfluidics, Artech House, 2002.

[8] E. Oosterbroek, A.V.D. Berg, Lab-on-a-chip:Miniaturized systems for (bio)chemical analysis and synthesis, Elsevier, 2003.

[9] T. Vilkner, D. Janasek, A. Manz, Micro total analysis systems. Recent developments, Anal. Chem. 76(2004) 3373-3386.

[10] P. Stonestreet, A. Harvey, A mixing-based design methodology for continuous oscillatory flow reactors, Chem. Eng. Res. Des. 80(2002) 31-44.

[11] K.B. Smith, M.R. Mackley, An experimental investigation into the scale-up of oscillatory flow mixing in baffled tubes, Chem. Eng. Res. Des. 84(2006) 1001-1011.

[12] N.M. Kashid, L. Kiwi-Minsker, Microstructured reactors for multiphase reactions:State of the art, Ind. Eng. Chem. Res. 48(2009) 6465-6485.

[13] J. Yoshida, H. Kim, A. Nagaki, Green and sustainable chemical synthesis using flow microreactors, ChemSusChem 4(2011) 331-340.

[14] R.S. Abiev, A.S. Galushko, Hydrodynamics of pulsating flow type apparatus:Simulation and experiments, Chem. Eng. J. 229(2013) 285-295.

[15] A. Nagaki, Y. Tomida, J. Yoshida, Microflow-system-controlled anionic polymerization of styrenes, Macromolecules 41(2008) 6322-6330.

[16] D.Wilms, J. Klos, H. Frey, Microstructured reactors for polymer synthesis:A renaissance of continuous flow processes for tailor-made macromolecules? Macromol. Chem. Phys. 209(2008) 343-356.

[17] M. Kakuta, F.G. Bessoth, A. Manz, Microfabricated devices for fluid mixing and their application for chemical synthesis, Chem. Rec. 1(2008) 395-405.

[18] K.Wang, Y.C. Lu, H.W. Shao, G.S. Luo, Improving selectivity of temperature-sensitive exothermal reactions with microreactor, Ind. Eng. Chem. Res. 47(2008) 4683-4688.

[19] S.W. Li, J.H. Xu, Y.Y. Wang, G.S. Luo, Controllable preparation of nanoparticles by drops and plugs flow in a microchannel device, Langmuir 24(2008) 4194-4199.

[20] N. Solehati, J. Bae, A.P. Sasmito, Numerical investigation of mixing performance in microchannel T-junction with wavy structure, Comput. Fluids 96(2014) 10-19.

[21] F. Schönfeld, V. Hessel, C. Hofmann, An optimised split-and-recombinemicro-mixer with uniform ‘chaotic’ mixing, Lab Chip 4(2004) 65-69.

[22] J. Aubin, D.F. Fletcher, J. Bertrand, C. Xuereb, Characterization of the mixing quality in micromixers, Chem. Eng. Technol. 26(2003) 1262-1270.

[23] J. Aubin,M. Ferrando, V. Jiricny, Current methods for characterising mixing and flow in microchannels, Chem. Eng. Sci. 65(2010) 2065-2093.

[24] Z.D. Liu, Y.C. Lu, J.W.Wang, G.S. Luo,Mixing characterization and scaling-up analysis of asymmetrical T-shaped micromixer:Experiment and CFD simulation, Chem. Eng. J. 181(2012) 597-606.

[25] P. Guichardon, L. Falk, Characterisation of micromixing efficiency by the iodide-iodate reaction system. Part I:Experimental procedure, Chem. Eng. Sci. 55(2000) 4233-4243.

[26] P. Guichardon, L. Falk, J. Villermaux, Characterisation of micromixing efficiency by the iodide-iodate reaction system. Part II:Kinetic study, Chem. Eng. Sci. 55(2000) 4245-4253.

[27] V. Hessel, H. Löwe, F. Schönfeld, Micromixers-A review on passive and active mixing principles, Chem. Eng. Sci. 60(2005) 2479-2501.

[28] W.L.H. Hallett, R. Günther, Flow and mixing in swirling flow in a sudden expansion, Can. J. Chem. Eng. 62(1984) 149-155.

[29] H.Y. Gan, Y.C. Lam, N.T. Nguyen, K.C. Tam, C. Yang, Efficient mixing of viscoelastic fluids in a microchannel at low Reynolds number, Microfluid. Nanofluid. 3(2007) 101-108.

[30] C.P. Jen, C.Y. Wu, Y.C. Lin, C.Y. Wu, Design and simulation of the micromixer with chaotic advection in twisted microchannels, Lab Chip 3(2003) 77-81.

[31] Y.M. Danilov, A.G.Mukhametzyanova, R.Y. Deberdeev, A.A. Berlin, Estimating the efficiency of mixing of liquid components in small tubular turbulent apparatuses, Theor. Found. Chem. Eng. 45(2011) 81-84.

[32] M.G. Lee, S. Choi, J.K. Park, Rapid multivortex mixing in an alternately formed contraction-expansion array microchannel, Biomed.Microdevices 12(2010) 1019-1026.

[33] A. Sau, Generation of streamwise vortices in square sudden-expansion flows, Phys. Rev. E 69(2004) 056307.

[34] J.S. Park, H.I. Jung, Multiorifice flow fractionation:Continuous size-based separation of microspheres using a series of contraction/expansion microchannels, Anal. Chem. 81(2009) 8280-8288.

[35] D. Liang, S.F. Zhang, A contraction-expansion helical mixer in the laminar regime, Chin. J. Chem. Eng. 22(2014) 261-266.

[36] Z.M. Gao, J. Han, Y.Y. Bao, Z.P. Li, Micromixing efficiency in a T-shaped confined impinging jet reactor, Chin. J. Chem. Eng. 23(2015) 350-355.

[37] B.Q. Liu, Y.K. Zhang,M.Q. Chen, P. Li, Z.J. Jin, Power consumption and flow field characteristics of a coaxial mixer with a double inner impeller, Chin. J. Chem. Eng. 23(2015) 1-6.

[38] S.H.Wong,M.C.L.Ward, C.W.Wharton, Micro T-mixer as a rapid mixingmicromixer, Sensors Actuators B Chem. 100(2004) 359-379.

[39] D. Bothe, C. Sternich, H.J.Warnecke, Fluid mixing in a T-shaped micro-mixer, Chem. Eng. Sci. 61(2006) 2950-2958.

[40] T. Matsunaga, H.J. Lee, K. Nishino, An approach for accurate simulation of liquid mixing in a T-shaped micromixer, Lab Chip 13(2013) 1515-1521.

[41] C. Galletti,M. Roudgar, E. Brunazzi, R.Mauri, Effect of inlet conditions on the engulfment pattern in a T-shaped micro-mixer, Chem. Eng. J. 185(2012) 300-313.

[42] A. Fani, S. Camarri, M.V. Salvetti, Investigation of the steady engulfment regime in a three-dimensional T-mixer, Phys. Fluids 25(2013) 064102.

[43] M.A. Sultan, K. Krupa, C.P. Fonte,M.I. Nunes,M.M. Dias, J.C.B. Lopes, R.J. Santos, Highthroughput T-jets mixers:An innovative scale-up concept, Chem. Eng. Technol. 36(2012) 323-331.

[44] P.V. Danckwerts, The definition and measurement of some characteristics of mixtures, Appl. Sci. Res. 3(1952) 279-296.

[45] I. Glasgow, N. Aubry, Enhancement of microfluidic mixing using time pulsing, Lab Chip 3(2003) 114-120.

[46] M. Roudgar, E. Brunazzi, C. Galletti, R. Mauri, Numerical study of split T-micromixers, Chem. Eng. Technol. 35(2012) 1291-1299.

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