Micromixer three-dimensional

Bottausci F, Mezic I, Meinhart CD (1818) Cardonne C (2004) Mixing in the shear superposition micromixer three-dimensional analysis. Philos Trans R Soc Lond Ser A Math Phys Eng Sci 362 1001-1018... 

Of all of the methods reviewed thus far in this book, only DNS and the linear-eddy model require no closure for the molecular-diffusion term or the chemical source term in the scalar transport equation. However, we have seen that both methods are computationally expensive for three-dimensional inhomogeneous flows of practical interest. For all of the other methods, closures are needed for either scalar mixing or the chemical source term. For example, classical micromixing models treat chemical reactions exactly, but the fluid dynamics are overly simplified. The extension to multi-scalar presumed PDFs comes the closest to providing a flexible model for inhomogeneous turbulent reacting flows. Nevertheless, the presumed form of the joint scalar PDF in terms of a finite collection of delta functions may be inadequate for complex chemistry. The next step - computing the shape of the joint scalar PDF from its transport equation - comprises transported PDF methods and is discussed in detail in the next chapter. Some of the properties of transported PDF methods are listed here. 

Park, S.-J., Kim, J. K., Park, )., Chung, S., Chung, C., Chang, ). K., Rapid three-dimensional passive rotation micromixer using the breakup process, J. Micromech. Microeng. 2004, 14, 6-14. 

Vijayendran, R.A., Motsegood, K.M., Beebe, D.J., Leckband, D.E., Evaluation of a three-dimensional micromixer in a surface-based biosensor Langmuir 2003, 19, 1824-1828. 

The Eulerian (bottom-up) approach is to start with the convective-diffusion equation and through Reynolds averaging, obtain time-smoothed transport equations that describe micromixing effectively. Several schemes have been proposed to close the two terms in the time-smoothed equations, namely, scalar turbulent flux in reactive mixing, and the mean reaction rate (Bourne and Toor, 1977 Brodkey and Lewalle, 1985 Dutta and Tarbell, 1989 Fox, 1992 Li and Toor, 1986). However, numerical solution of the three-dimensional transport equations for reacting flows using CFD codes are prohibitive in terms of the numerical effort required, especially for the case of multiple reactions with... 

On the other hand, passive chaotic micromixers typically use complex three-dimensional twisted conduits fabricated in various substrates such as silicon [13], polydimethylsiloxane (PDMS) [14], ceramic tape [15], or glass [13] to create 3-D steady flow velocity with a certain complexity to achieve chaotic advection. T q)ical examples of the aforementioned two routes to achieve chaotic advection and mixing in LOC devices are presented in the following. 

Recently Lim et al. [92] presented a three-dimensionally micro-mixer, named crossing manifold micromixer (Fig. 5b). The micromixer was able to perform almost complete mixing of 90% channel length of 250 pm. 

Che-Hsin L, Chien-Hsiung T, Lung-Ming F (2005) A rapid three-dimensional vortex micromixer utilizing self-rotation effect under low Reynolds number conditions. J Micromech Microeng 15 935. http //dx.doi.Org/10.1088/0960-1317/15/5/006 Bessoth F, deMello A, Manz A (1999) Microstructure for efficient continuous flow mixing. Anal Commun 36(6) 213-215... 

Lee S, Kim D, Lee S, Kwon T (2006) A split and recombination micromixer fabricated in a PDMS three-dimensional structure. J Micromech Microeng 16 1067. http //dx.doi.org/... 

Vijayendran R, Motsegood K, Beebe D, Leckband D (2003) Evaluation of a three-dimensional micromixer in a surface-based biosensorf. Langmuir 19(5) 1824-1828 Lin Y, Gerfen G, Rousseau D, Yeh S (2003) Ultrafast microfluidic mixer and freezequenching device. Anal Chem 75(20) 5381-5386... 

Long M, Sprague M, Grimes A, Rich B, Khine M (2009) A simple three-dimensional vortex micromixer. Appl Phys Lett 94 133501... 

Passive Micromixers, Fig. 1 A generic two-input two-output mixer including lamination and splitting shown in free three-dimensional space, (a) Horizontal lamination and (b) vertical lamination [2]... 

Micromixers Based on Three-Dimensional Serpentine Structures... 

Figure 4.8 Three-dimensional velocity field of of-planecomponentofthevelocity,z-component stereo- X-PIV measurements in the mixing zone is displayed colour coded. Only the lower half of of a T-shaped micromixer at Re = 120. The flow is the 3D scan from z = 22 to lOOpm in the center of laminar and station a 7. The in-plane velocity the channel ofthe 800 x 200 Xm cross-section is distribution is presented as vectors and the out- shown [12] (by courtesy of Springer-Verlag).

Figure 4.12 Three-dimensional concentration field, T-shaped micromixer, cross-section geometry 400 x 100 im - beginning of the mixing channel (Re=130).

C.-H. Lin, C.-H. Tsai, L.-M. Fu, A rapid three-dimensional vortex micromixer ultilizing self-rotation effects under low Reynolds number conditions. J. Micromech. Microeng., 2005, 35, 935-943. 

S. J. Park, etal.. Rapid Three-Dimensional Passive Rotation Micromixer Using the Brackup Process./. Micromech. Microeng., 2004, 24, 6-14. 

Passive Micromixers, Figure 6 (a) Schematic of the three-dimensional serpentine channel. Viewing windows in the channel are labeled 1-10. (b) Schematic of zigzag channel, (c) Schematic of straight channel [9]... 

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