Microchannels nitrogen/water flows

Figure 4.39 Flow patterns for the nitrogen-water (a) Slug flow Ug — 0.5 m/s, U = 0.1 m/s (b) system observed for the smooth mixer in the annular flow Ug — 5.5 m/s, U = 0.07 m/s (c) microchannel used attheTU/e. The images were ring flow Ug = 20m/s, U = 0.2m/s (d) churn recorded atthe indicated superficial gas (Ug) and flow Ug = 50m/s, U — 0.5 m/s (by courtesy of superficial liquid velocities (U ). The channel has Wiley-VCH Verlag GmbH) [279]. a rectangular cross section of 100 pm X 50 pm.

Figure 9.14 Flow patterns of nitrogen/water indicated. The channel has a rectangular cross-flows in microchannels of the Taylor flow section of lOOpm x 50 (im. Source By courtesy...

Figure 9.15 Flow patterns for the nitrogen/water system observed for the smooth mixer in the microchannel used at the TU/e. The images were recorded at the indicated superficial gas (Ug) and superficial liquid velocities (U ). The channel has a rectangular...

The experimental data obtained in conventional size channels and micro-channels with diameters between 100 pm and 6.0 mm are examined to further elucidate and understand the differences in two-phase flow characteristics between the microchannels and conventional size channels. Since two separate sets of experiments have been conducted using air and water in acrylic channels with diameters between 500 pm and 6.0 mm, and nitrogen gas-water in fused silica channels with diameters between 50 and 500 pm, the authors refer to the former channels as conventional size channels, and the latter channels as micro-channels for convenience. Two different inlet sections were covered in micro-channel experiments, a gradually reducing section and a T-junction. 

Figure 9.7 Maps of the water-nitrogen two-phase flow regimes in the microchannels (I) 100 X 50 pm [40], (II) 50 X 50 pm [45], (III) 300 x 100 pm [40], (IV) Ref [46], (V) Ref [47], and (VI) Ref [44]. The lines represent the boundaries of the transitions between regimes (la), (lb) slug/slug-annular (2a), (2b), (2c) slug-aimular/annulai (3a), (3b) annular/churn and (4) slug/ churn regimes.

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