OJFD  Vol.4 No.5 , December 2014
A Micromixer Using the Taylor-Dean Flow: Effect of Inflow Conditions on the Mixing
Abstract: Chaotic mixing in a curved-square channel flow is studied experimentally and numerically. Two walls of the channel (inner and top walls) rotate around the center of curvature and a pressure gradient is imposed in the direction toward the exit of the channel. This flow is a kind of Taylor-Dean flows. There are two parameters dominating the flow, the Dean number De (∝ the pressure gradient or the Reynolds number) and the Taylor number Tr (∝ the angular velocity of the wall rotation). In the present paper, we analyze the physical mechanism of chaotic mixing in the Taylor-Dean flow by comparing experimental and numerical results. We produced a micromixer model of the curved channel several centimeters long with square cross section of a few millimeters side. The secondary flow was measured using laser induced fluorescence (LIF) method to examine secondary flow characteristics. We also performed three-dimensional numerical simulations for the exactly same configuration as the experimental system to study the mechanism of chaotic mixing. It is found that good mixing performance is achieved for the case of De ≤ 0.1Tr, and that mixing efficiency changes according to the difference in inflow conditions. The flow is studied both experimentally and numerically, and both results agree with each other very well.
Cite this paper: Kawabe, T. , Hayamizu, Y. , Yanase, S. , Gonda, T. , Morita, S. , Ohtsuka, S. and Yamamoto, K. (2014) A Micromixer Using the Taylor-Dean Flow: Effect of Inflow Conditions on the Mixing. Open Journal of Fluid Dynamics, 4, 463-471. doi: 10.4236/ojfd.2014.45037.

[1]   Stroock, A.D., Dertinger, S.K.W., Ajdari, A., Mezic, I., Stone, H.A. and Whitesides, G.M. (2002) Chaotic Mixer for Microchannels. Science, 295, 647-651.

[2]   Kim, D.S., Lee, I.H., Kwon, T.H. and Cho, D.W. (2003) A Novel Chaotic Micromixer: Barrier Embedded Kenics Micromixer. Proceedings of 7th International Conference on Miniaturized Chemical and Biochemical Analysis Systems, Squaw Valley, 5-9 October 2003, 73-76.

[3]   Sato, H., Ito, S., Tajima, K., Orimoto, N. and Shoji, S. (2005) PDMS Microchannels with Slanted Grooves Embedded in Three Walls to Realize Efficient Spiral Flow. Sensors and Actuators A: Physical, 119, 365-371.

[4]   Niu, X.Z. and Lee, Y.-K. (2003) Efficient Spatial-Temporal Chaotic Mixing in Microchannels. Journal of Micromechanics and Microengineering, 13, 454-462.

[5]   Tabeling, P., Chabert, M., Dodge, A., Jullien, C. and Okkels, F. (2004) Chaotic Mixing in Cross-Channel Micromixers. Philosophical Transactions of the Royal Society A, 362, 987-1000.

[6]   Hayamizu, Y., Yanase, S., Morita, S., Ohtsuka, S., Gonda, T., Nishida, K. and Yamamoto, K. (2012) A Micromixer Using the Chaos of Secondary Flow: Rotation Effect of Channel on the Chaos of Secondary Flow. Open Journal of Fluid Dynamics, 2, 195-201.

[7]   Yamamoto, K., Wu, X.Y., Nozaki, K. and Hayamizu, Y. (2006) Visualization of Taylor-Dean Flow in a Curved Duct of Square Cross-Section. Fluid Dynamics Research, 38, 1-18.

[8]   The Japan Society of Mechanical Engineers (1971) JSME Data Book: Hydraulic Losses in Pipes and Ducts. The Japan Society of Mechanical Engineers, Tokyo, 68-72.

[9]   OpenFOAM Official Site.

[10]   Funakoshi, M. (2008) Chaotic Mixing and Mixing Efficiency in a Short Time. Fluid Dynamics Research, 40, 1-33.