CFD Modeling of Mixing Enhancement in a Pitted Micromixer by High Frequency Ultrasound Waves
Use of ultrasound waves is one of the techniques for increasing the mixing and mass transfer in the microdevices. Ultrasound propagation into liquid medium leads to stimulation of the fluid, creates turbulence and so increases the mixing performance. In this study, CFD modeling of two-phase flow in a pitted micromixer equipped with a piezoelectric with frequency of 1.7 MHz has been studied. CFD modeling of micromixer at different velocity of fluid flow in the absence of ultrasound waves and with ultrasound application has been performed. The hydrodynamic of fluid flow and mixing efficiency for using ultrasound has been compared with the layout of no ultrasound application. The result of CFD modeling shows well agreements with the experimental results. The results showed that the flow pattern inside the micromixer in the absence of ultrasound waves is parallel, while when ultrasound has been applied, it is not parallel. In fact, propagation of ultrasound energy into the fluid flow in the studied micromixer changed the hydrodynamic and the forms of the flow pattern and caused to mixing enhancement. In general, from the CFD modeling results, it can be concluded that the applying ultrasound energy into the liquid medium causes an increase in the turbulences and mixing and consequently, improves the mass transfer rate within the micromixer.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.3298775Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 217
 N. Aoki, K. Mae, “Effects of channel geometry on mixing performance of micromixers using collision of fluid segments”. Chem. Eng. J. vol. 118, pp. 189–197, 2006.
 A. C. Perez, S. Barrass, A. Gavriilidis, “Residence time distributions in microchannels: Comparison between channels with herringbone structures and a rectangular channel”. Chem. Eng. J. vol. 160, pp. 834–844, 2010.
 A. G. Kanaris, A. A. Mouza. “Numerical investigation of the effect of geometrical parameters on the performance of a micro-reactor”. Chem. Eng. Sci. vol. 66, pp. 5366–5373, 2011.
 V. Hessel, H. Lowe, F. Schonfeld. Micromixers—a review on passive and active mixing principles. Chem. Eng. Sci. 60 (2005) 2479 – 2501.
 F. H. Kakavandi, M. Rahimi , O. Jafari, N. Azimi, “Liquid–liquid two-phase mass transfer in T-type micromixers with different junctions and cylindrical pits”. Chem. Eng. Process. Vol. 107, pp. 58-67, 2016.
 J. M. Commenge, L. Falk, “Villermaux–Dushman protocol for experimental characterization of micromixers”. Chem. Eng. Process. Vol. 50, pp. 979– 990, 2011.
 X. Shang, X. Huang, C. Yang C., “Mixing enhancement by the vortex in a microfluidic mixer with actuation”. Exp. Therm. Fluid Sci. vol. 67, pp. 57–61, 2015.
 F. G. Ergin, B. B. Watz, K. Erglis, A. Cebers, “Time-resolved velocity measurements in a magnetic micromixer”. Exp. Therm. Fluid Sci. vol. 67, pp. 6-13, 2015.
 Y. Wang, J. Zhe, B. T. F. Chung, P. Dutta, “A rapid magnetic particle driven micromixer, Microfluid Nanofluid”. 4 (2008) 375–389.
 M. D. Luque de Castro, F. Priego Capote, “Analytical Applications of Ultrasound”, First Elsevier Publisher, Spain, 2007.ed.
 N. P. Dhanalakshmi, R. Nagarajan, N. Sivagaminathan, B. V. S. S. S. Prasad, “Acoustic enhancement of heat transfer in furnace tubes”, Chem. Eng. Process. Vol. 59, pp. 36–42, 2012.
 J. A. Cárcel, J. V. García-Pérez, J. Benedito, A. Mulet, “Food process innovation through new technologies: Use of ultrasound”, Journal of Food Engineering. Vol. 110, pp. 200–207, 2012.
 M. Rahimi, N. Azimi, F. Parvizian, “ Using microparticles to enhance micromixing in a high frequencycontinuous flow sonoreactor”. Chem. Eng. Process. Vol. 70, pp. 250– 258, 2013.
 F. Parvizian, M. Rahimi., N. Azimi, “Macro- and micromixing studies on a high frequency continuous tubular sonoreactor”. Chem. Eng. Process. Vol. 57– 58, pp. 8– 15, 2012.
 F. Parvizian, M. Rahimi, N. Azimi, A. A. Alsairafi, “CFD Modeling of Micromixing and Velocity Distribution in a 1.7-MHzTubular Sonoreactor”. Chem. Eng. Technol. Vol. 37, No. 1, pp. 1–11, 2014.
 M. Rahimi, N. Azimi, F. Parvizian, A. A. Alsairafic “Computational Fluid Dynamics modeling of micromixing performance in presence of microparticles in a tubular sonoreactor”. Comput. Chem. Eng. Vol. 60, pp. 403– 412, 2014.
 FLUENT 6.3.,“User’s manual to FLUENT 6.3.” Centrera Resource Park, 10 Cavendish Court, Lebanon (2006) USA: Fluent Inc.