Micro T- mixer: The effect of scaling factor and mixing angel
Keywords:
micromixer, geometry scaling factorAbstract
Different phenomena observed in various experiments indicate that the flowing mechanisms of liquids in microchannels are still not understood clearly. Computational fluid dynamics (CFD) simulation was used to simulate liquid flow in a T-shaped micromixer whose structural dimensions and operating conditions were varying. The results show that, the formation of vortices in the mixing zone arises through the influence of a T-junction (changes flow direction and gives rise to a secondary flow). After the mixing zone, the flow is almost fully developed and mixing occurs by a molecular diffusion mechanism only. The results also show that the mixing angle had a significant effect on the T-mixer performance. This can be attributed to the fact that for the engulfment flow regime, there is an optimum T-angle at which the effect of sharp bend reaches a strength value. If liquids enter into inlets with the same velocities, the flow was symmetrical; otherwise, the symmetry was broken up. The asymmetrical inlet velocities help to promote mixing quality. To illustrate the differences of liquids flow between macro- and micro-scale, the mixer is scaled in proportion, and the simulation shows that the smaller the mixer, the better the mixing quality.
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References
[1]. Brody J P, Yager P, Goldstein R E, et al. Biotechnology at Low Reynolds Numbers [J]. Biophys., 1996, 71.
[2]. Jensen K F. Microreaction Engineering - is Small Better? [J]. Chem. Eng. Sci., 2001, 56.
[3]. Marteza Bayareh, Mohsen Nazemi, et al. Active and Passive micromixer: A comprehensive review [J]. Chemical Engineering and Processing- Process Intensification, 2020, 147.
[4]. Clia- Yen Lee, Wen- Teng Wang, et al. Passive micromixers in microfluidic system: A review [J]. Chemical Engineering Journal, 2016, 288.
[5]. Najafpour A., Hosseinzadeh K. et al. Numerical Study of Mixing Performance in T- Junction Passive Micromixing with Twisted Design [J]. Chemical Engineering Processing- Process Intensification, 2023, 194.
[6]. Shusaku A., Shinji K., et al. Chaotic- flow- driven mixing in T- and V shaped micromixers [J]. Chemical Engineering Journal, 2024,489.
[7]. Kockmann N, Engler M, Föll C, et al. Liquid Mixing in Static Micromixers with a Various Cross Sections [C]. 1st Int. Conf. Microchannels Minichannels, New York USA, 2003, 1121.
[8]. Johnson T, Ross D, Locascio L. Rapid Microfluidic Mixing [J]. Anal. Chem., 2002, 74.
[9]. Kockmann N, Föll C, Woias P. Flow Regimes and Mass Transfer Characteristics in Static Micromixers [J]. Proc. SPIE 2003, 4982: 319- 329.
[10]. Engler M, Föll C, Kockmann N, et al. Investigations of Liquid Mixing in Static Micromixers [C]. In: Proc. 11 Eur. Conf. Mixing, Hamberg Germany, 2003, 277- 284.
[11]. Hoffmann M, Raebiger N, Schlueter M, et al. Experimental and Numerical Investigations of T- shaped Micromixers [C]. In: Proc. 11 Eur. Conf. Mixing, Hamberg, Germany, 2003.
[12]. Wong H S, Ward M C L, Wharton C W. Micro T- mixer as a Rapid Mixing Micromixer [J]. Sensors Actuators B, 2004, 100.
[13]. Qian D, Lawal A. CFD Simulations of Gas and Liquid Slugs for Taylor Flow in a Microchannel [C]. 3 Int. Conf. Microchannels Minichannels, Toronto, Canada, 2003.
[14]. Hoffmann M, Schlüter M, Rábiger N. Experimental Investigation of Liquid- Liquid Mixing in T- Shaped Micro- mixers Using μ- LIF and μ- PIV [J]. Chem. Eng. Sci., 2006, 61.
[15]. Bothe D, Stelmich C, Warnecke H. Fluid Mixing in a T- shaped Micro- mixer [J]. Chem. Eng. Sci., 2006, 61.
[16]. Goullet A, Glasgow I, Aubry N. Effects of Microchannel Geometry on Pulsed Flow Mixing [J]. Mech. Res. Commun., 2006, 33.
[17]. Engler M, Kockmann N, Kiefer T, et al. Numerical and Experimental Investigations on Liquid Mixing in Static Micromixers [J]. Chem. Eng. J., 101.
[18]. Schwarzer H- C, Peukert W. Combined Experimental/Numerical Study on the Precipitation of Nanoparticles [J]. AIChE J., 2004, 50.
[19]. Schwarzer H- C, Michael M, Peukert W. Characterization of Mixing in a T- mixer: A combined Experimental and Numerical Study [C]. 11 Eur. Conf. Mixing, Hamberg, 2003.
[20]. Schwarzer H- C, Peukert W. Tailoring Particle Size through Nanoparticle Precipitation [J]. Chem. Eng. Commun., 2004, 191.
[21]. Schwarzer H- C, Schwertfirm F, Manhart M, et al. Predictive Simulation of Nanoparticle Precipitation based on the Population Balance Equation [J]. Chem. Eng. Sci., 2006, 61.
[22]. Gradl J, Schwarzer H- C, Schwertfirm F, et al. Precipitation of Nanoparticles in a T- mixer: Coupling the Particle Population Dynamics with Hydrodynamics through Direct Numerical Simulation [J]. Chem. Eng. Process, 2006, 45.
[23]. Zhao Y C, Ying Y, Chen G W, et al. Characterization of Micro- mixing in T- shaped Micro- mixer [J]. Journal of Chemical Industry and Engineering (China), 2006, 57.
[24]. Lin Y- C, Chung Y- C, Wu C- Y. Mixing Enhancement of the Passive Microfluidic Mixer with J- shaped Baffles in the Tee Channel [J]. Biomed. Microdevices, 2007, 9.
[25]. Fu L- M, Tsai C- H. Design of Interactively Time- Pulsed Microfluidic Mixers in Microchips using Numerical Simulation [J]. Jap. J. Appl. Phys., 2007, 46.
