MicroChannel Flow

Knight RW, Hall DJ, Goodling JS, Jaeger RC (1992) Heat sink optimization with apphcation to micro-channels. IEEE Trans Comp Hybrids Manuf Technol 15 832-842 Kohl MJ, Abdel-Khalik SI, Jeter SM, Sadowski DL (2005) An experimental investigation of microchannel flow with internal pressure measurements. Int J Heat Mass Transfer 48 1518-1533 Lasance CJM, Simons RE (2005) Advances in high performance cooling for electronics. 

ReveUin R, Dupont V, Ursenbacher T, Thome JR, Zun I (2006) Characterization of diabatic two-phase flows in microchannels flow parameter results for R-134a in a 0.5 mm channel. Int J Multiphase Flow 32 755-774... 

Hoiiuchi K, Dutta P (2004) Joule heating effects in electroosmotically driven microchannel flows. 

Li HY, Tseng FC, Pan C (2004) Bubble dynamics in micro-channels. Part II two parallel microchannels. Int J Heat Mass Transfer 47 5591-5601 Li J, Cheng P (2004) Bubble cavitation in a micro-channel. Int J Heat Mass Transfer 47 2689-2698 Liu D, Lee PS, Gaiimella SV (2005) Prediction of the onset of nucleate boiling in microchannel flow. Int J Heat Mass Transfer 48 5134-5149... 

Figure 11.19 Manufacturing scale-up device with submanifolds for passive flow distribution to feed thousands of parallel microchannels. Flow is mapped using ranges to show variations from a normalized value.

Oh, C. K., Oran, E. S., Sinkovits, R. S., Gomputations of high-speed, high Knudsen number microchannel flow,... 

G. V, Direct simulation methods for low-speed microchannel flows, J. Thermophys. Heat Transfer 14, 3 (2000) 368-378. 

A vertically-averaged formulation of catalytic reactions in microchannel flows, in Matlosz, M., Ehrfeld, W., Baselt,... 

S)-ibuprofen by means of ionic liquid flow within a microfluidic device. (B, Bottom) Photographs of the three-phase flow in the microchannel (a) center near the inlets of the microchannel, (b and c) arc of the microchannel, and (d) center near the outlets of the microchannel. Flow rates of the aqueous phase and the ionic liquid flow phase in (a-d) were 1.5 and 0.3 mL/h, respectively. (Reprinted from Huh, Y.S., Jun, Y.S., Hong, Y.K., Hong, W.H., and Kim, D.H., /. Mol. Catal. B, 43, 96-101, 2006. Copyright 2006 Elsevier. With permission.)... 

Devasenathipathy, S., Santiago, J.G., Takehara, K., Particle tracking techniques for electrokinetic microchannel flows. Anal. Chem. 2002, 74(15), 3704—3713. 

It is usually necessary to match the refractive indices of two fluids (and the transparent wall of flow passage in some cases particularly for microchannel flow). For example, in an experimental study on the selfpreserving structure of steady round buoyant turbulent plums in cross flow (Diez et al., 2005), planar-LIF (PLIF) and PIV techniques are utilized to measure the mean concentration of source fluid and mean velocity fields simultaneously. Both PLIF and PIV measurements in this study necessitate matching the indices of refraction of the source (water solution of potassium phosphate, monobasic KH2PO4, containing Rhodamine 6G dye) and ambient fluids (ethyl alcohol/water) to avoid scattering the laser beam away from the buoyant flow. Visual inspection... 

S. Kandlikar and W. Grande. Evolution of microchannel flow passages — thermohydraulic performance and fabrication technology . Heat Transfer Engineering, 25, pp. 3-17 (2003). 

Kandlikar, S.G., (2001), Two-phase flow patterns, pressure drop and heat transfer during boiling in minichannels and microchannels flow passages of compact evaporators. Keynote Lecture presented at the Engineering foundation Conference on Compact Heat Exchangers, Davos, Switzerland, July 1-6. 

A microfluidic sensor to detect fluorescently labelled DNA was developed by Khur and co-workers [29], Photopatteming was obtained with carbene-generating photobiotin and allowed fabrication of homogeneous regions of immobilized biotin and the control of the spatial distribution of DNAs in a microchannel-flow-based sensor. 

The interest in the area of microchannel flow and heat transfer has increased substantially during the last decade due to developments in the electronic industry, microfabrication technologies, biomedical engineering, etc. In general, there also seems to be shift in the focus of published articles. 

Dispersion, the tendency for ordered molecules to decrease gradients and local concentration, is caused by both molecular diffusion and nonuniform bulk liquid motion. High dispersion rates may be advantageous for mixing and chemical reactions, but are undesirable in separation and purification applications. For separations, minimizing dispersion improves resolution and sensitivity [3] and yields improved dynamics for concentration and purification [4]. As a consequence, the physical processes that lead to dispersion have been a subject of intense interest for more than a century. In recent years, the development of the concept of the micro-total analysis system (p,TAS) or labs on a chip has motivated further exploration of dispersion in microchannel flows. 

Lin, H., et al.. Instability of electrokinetic microchannel flows with conductivity gradients. Phys. Fluids, 2004, 16 1922-1935. 

Wilson, D.J., Konermann, L., Ultrarapid desalting of protein solutions for electrospray mass spectrometry in a microchannel flow device. Ana/. Chem., 11, 6887-6894, 2005. 

Knowledge of pressure drop during two-phase flow in microchannels is essential for the design of energy efiicient systems. However, despite its importance only relatively few studies are available in literature concerning pressure drop in liquid-liquid microchannel flows (Chakrabarti et al. 2005 Kashid and Agar 2007 Salim et al. 2008 Jovanovic et al. 2011), compared to those available for gas-liquid flows (Triplett et al. 1999 Chen et al. 2002 Kawahara et al. 2002 Kreutzer et al. 2005). 

Flow boiling in microchannels Flow boiling in narrow channels... 

Yang J, Kwok DY (2003) Effect of liquid slip in electrokinetic parallel-plate microchannel flow. J Colloid Interface Sci 260 225-233... 

With typical microchannel flow rates usually smaller than 10 pL/min, a microflow has to be capable of continuous and uniform perfusion of media as well as steady culturing conditions. The flow must have a distribution such that adherent cells are not exposed to signiflcant shear stress. Cells in suspension are assayed either while carried by bulk microflow or, more often, after immobilization in the chip. Common immobilization techniques in microchannels are hydrodynamic trapping [6, 7] and adsorbing cells to a chemically treated surface [8]. 

Nemst-Planck equation and the Boltzmann distribution predict identical ionic concentration distributions in the microchannel flow. Therefore, it can be concluded that from a microfluidic applications viewpoint, the Boltzmann distribution is adequate to describe the ionic concentration distributions in electrokinetic flow. 

Heat transfer in microchannel flow Single-phase convective flows in microchannels Single-phase forced convection in microchannels... 

Since the temperature rise along the microchannel can be very large at very low values of the Reynolds number, for a fixed value of the wall heat flux, the thermophysical properties cannot be considered as constants in other words, the effects related to the variation of the thermophysical properties with temperature tend to be in general coupled with conjugate effects. It has been numerically demonstrated that in microchannel flows it becomes very important to take into account the variation of the fluid viscosity with the temperature in contrast, the other thermophysical properties can be considered as constant. 

Condition where the channel walls are no longer wetted by the flowing liquid, a transition to the drywall condition as a result of high heat flux imposed at the wall during microchannel flow boiling conditions. 

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