Gas–liquid two-phase flow splitting at microchannel junctions with different branch angles

Abstract In the present work, the phase split occurring at microchannel junctions with the square cross-section of 0.5×0.5 mm 2 was investigated experimentally under adiabatic condition. Microchannel junctions with five different branch angles varying from 30° to 150° were manufactured. Two different methods of controlling gas/liquid division from the run/the branch were employed, suitable for acquiring splitting data for a wide range of flow patterns covering slug flow, slug–annular flow and annular flow. The inlet superficial velocities varied from 0.8 to 21.3 m/s for gas phase (nitrogen), and from 0.019 to 0.356 m/s for liquid phase (pure water). The high speed recording technique was utilized to elucidate the fluid dynamics of two-phase flow splitting at microchannel junctions. Data analysis revealed that the phase splitting curves did not simply take on a transitional characteristic when the inlet flow pattern changed from slug flow to annular flow. Furthermore, the liquid taken off from the branch did not decrease with increasing branch angle for all kinds of inlet flow patterns. Finally, by comparing the present data with those of mini- and macro-scale research, it was found that more liquid was taken off from the branch at microchannel junctions.

[1]  Shangfu Li,et al.  Formation of monodisperse microbubbles in a microfluidic device , 2006 .

[2]  D. Poulikakos,et al.  On two-phase flow patterns and transition criteria in aqueous methanol and CO2 mixtures in adiabatic, rectangular microchannels , 2009 .

[3]  Ibrahim Hassan,et al.  Adiabatic two phase flow distribution and visualization in scaled microchannel heat sinks , 2007 .

[4]  J. Köhler,et al.  Nanoliter segment formation in micro fluid devices for chemical and biological micro serial flow processes in dependence on flow rate and viscosity , 2005 .

[5]  T. Bayraktar,et al.  Characterization of liquid flows in microfluidic systems , 2006 .

[6]  G. Geraci,et al.  Effect of inclination on circumferential film thickness variation in annular gas/liquid flow , 2007 .

[7]  Barry J. Azzopardi,et al.  Controlling the phase separation of gas–liquid flows at horizontal T-junctions , 2007 .

[8]  Jinfang Chen,et al.  Phase split of nitrogen/non-Newtonian fluid two-phase flow at a micro-T-junction , 2011 .

[9]  Masahiro Kawaji,et al.  The effect of channel diameter on adiabatic two-phase flow characteristics in microchannels ☆ , 2004 .

[10]  Kjell H. Bendiksen,et al.  An experimental investigation of the motion of long bubbles in inclined tubes , 1984 .

[11]  B. J. Azzopardi,et al.  The effect of flow patterns on two-phase flow in a T junction , 1982 .

[12]  Barry J. Azzopardi,et al.  The Phase Separation Capabilities of Two T-Junctions Placed in Series , 2004 .

[13]  Tohru Fukano,et al.  Characteristics of gas-liquid two-phase flow in a capillary tube , 1993 .

[14]  Richard T. Lahey,et al.  Phase separation in dividing two-phase flows , 1988 .

[15]  Kui He,et al.  The effect of flow pattern on split of two-phase flow through a micro-T-junction , 2011 .

[16]  Said I. Abdel-Khalik,et al.  Gas–liquid two-phase flow in microchannels Part I: two-phase flow patterns , 1999 .

[17]  Transport of wetting liquid plugs in bifurcating microfluidic channels. , 2007, Journal of colloid and interface science.

[18]  Ovadia Shoham,et al.  A unified model for stratified-wavy two-phase flow splitting at a reduced T-junction with an inclined branch arm , 1997 .

[19]  Richard T. Lahey,et al.  The analysis of phase separation phenomena in branching conduits , 1983 .

[20]  Ziping Feng,et al.  Two-phase flow in microchannels , 2002 .

[21]  Phase splitting of wet steam in annular flow through a horizontal impacting tee , 1992 .

[22]  S. Hsieh,et al.  Liquid flow in a micro-channel , 2006 .

[23]  B. J. Azzopardi,et al.  The split of vertical two-phase flow at a small diameter T-junction , 2006 .

[24]  K. C. Hong.  Two-Phase Flow Splitting at a Pipe Tee , 1978 .

[25]  A. Kawahara,et al.  Investigation of two-phase flow pattern, void fraction and pressure drop in a microchannel , 2002 .

[26]  Do Hyun Kim,et al.  Droplet-based microextraction in the aqueous two-phase system. , 2010, Journal of chromatography. A.

[27]  Wang Cai,et al.  Numerical study on air-side performance of an integrated fin and micro-channel heat exchanger , 2010 .

[28]  Barry J. Azzopardi,et al.  Slug flow in small diameter pipes and T-junctions , 2005 .

[29]  Jinfang Chen,et al.  Experimental investigation of two-phase distribution in parallel micro-T channels under adiabatic condition , 2012 .

[30]  Martin A. Abraham,et al.  Bubble-train flow in capillaries of circular and square cross section , 1995 .

[31]  Predrag Stojan Hrnjak,et al.  Characterization of Two -Phase Flow in Microchannels , 2002 .

[32]  L. C. Walters,et al.  Two-phase pressure drop and phase distribution at reduced tee junctions , 1998 .

[33]  David A. Weitz,et al.  Mixing characterization inside microdroplets engineered on a microcoalescer , 2007 .

[34]  A. Gavriilidis,et al.  Axial mass transfer in Taylor flow through circular microchannels , 2007 .

[35]  D. Bothe,et al.  Fluid mixing in a T-shaped micro-mixer , 2006 .

[36]  Kui He,et al.  The effect of surface tension on phase distribution of two-phase flow in a micro-T-junction , 2011 .

[37]  Barry J. Azzopardi,et al.  The split of stratified gas–liquid flow at a small diameter T-junction , 2005 .

[38]  Ovadia Shoham,et al.  Two-phase flow splitting in a tee junction—experiment and modelling , 1987 .

[39]  Holger Löwe,et al.  Development of micro chemical, biological and thermal systems in China: A review , 2010 .

[40]  Liu Qi,et al.  Gas-liquid two-phase flow division at a micro-T-junction , 2010 .

[41]  Min-Soo Kim,et al.  Experimental study on microchannel heat sinks considering mass flow distribution with non-uniform heat flux conditions , 2010 .

[42]  Barry J. Azzopardi,et al.  Plant Application of a T-Junction as a Partial Phase Separator , 2002 .