Microchannel geometry

S. Sugiura, M. Nakajima, and M. Seki Prediction of Droplet Diameter for MicroChannel Emulsification Prediction Model for Complicated MicroChannel Geometries. Ind. Eng. Chem. Res. 43, 8233 (2004). 

Bandhauer, T. M. (2002) Heat Transfer in MicroChannel Geometries During Condensation cfRI34a, Master of Science Thesis, Mechanical Engineering, Iowa State University, Ames, lA, p. 201. 

BINARY-FLUID HEAT AND MASS TRANSFER IN MICROCHANNEL GEOMETRIES FOR MINIATURIZED THERMALLY ACTIVATED ABSORPTION HEAT PUMPS... 

Binary-Fluid Heat and Mass Transfer in MicroChannel Geometries for Miniaturized Thermally Activated Absorption Heat Pumps 339... 

The nature of boiling heat transfer in a channel with the gap less than the capillary is also studied and presented. The condensation flow mechanisms, pressure drop and heat transfer in microchannels, role of microscale heat transfer in augmentation of nucleate boiling and flow boiling heat transfer, binary-fluid heat and mass transfers in microchannel geometries for miniaturized thermally activated absorption heat pumps, evaporation heat... 

M. D. Determan, Experimental and Analytical Investigation of Ammonia-Water Desorption in MicroChannel Geometries, Master s Thesis, Georgia Institute of Technology, August, 2005. 

So far we have discussed the droplet dynamics in single straight microchannels only. Droplet dynamics in other microchannel geometries, on the other hand, may be associated with certain distinctive features that are not usually apparent with flows in single straight microchannels. As an example, one may cite the case of droplet motion in a microchannel geometry that is characterized with a sudden contraction in the cross-sectional... 

The microchannel geometry and flow conditions can be optimized using adaptive simulations. More extensive research can be directed toward this aspect. 

Li and Peterson [9] investigated numerically the thermal performance of silicon-based microchannel heat sinks using a simplified heat transfer model, i.e., 2D fluid flow and 3D heat transfer analysis. The tested rectangular microchannels had widths ranging from 20 to 220 pm and depths ranging from 100 to 400 pm. The effect of microchannel geometry... 

Automatic macromodel extraction that takes advantage of high-fidelity device simulations (e.g., FEM, FVM, and BEM) to extract RLC values in irregular microchannel geometries has also been reported. Turowski et al. [11] approximate the microfluidic Tesla valve as an/ L circuit (serial connection of a resistor R and an inductor L in Fig. 5) and performed both steady and transient analysis to extract its fluidic resistance and inductance. The macromodels are then stitched together for an overall system simulation on the pumping performance. 

Equation 24 can be adopted as a criterion to predict the upper limit of significance of viscous dissipation in a microchannel. Equation 24 allows, for a fixed microchannel geometry and hydraulic diameter, the calculation of the values of the Reynolds number for which the temperature rise between inlet and outlet is equal to or greater than 1 K. 

Besides, even in the case of transparent device, the analysis can be done only for very simple microchannel geometry without internal structures. 

Example 6.4 Volumetric mass transfer coefficient for different microchannel geometries... 

Estimate and plot the volumetric mass transfer coefficient ikQo) for different microchannel geometries such as slit, rectangle HIW = 0.25), circular, and square for different hydraulic diameter ranging from 50 to 1000 pm neglecting the influence of entrance zone. The diffusion coefficient of gas ( > ,) is 10-3 J.-1... 

As in gas-liquid systems, this flow is formed based on the type of microchannel geometry used flow symmetric geometry forms annular flow, while flow asymmetric forms parallel flow. This flow regime is observed at elevated flow rates in the microchannel without static internals - the higher the flow velocity, the better the stability. The shear force of the continuous phase is dominant over the surface tension force and, therefore, the dispersed phase flows straight forming annular or parallel flow. 

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