Abstract
In this paper, numerical investigation of slug formation mechanism of gas–liquid two-phase flow in a T-junction microchannel has been carried out. A two-dimensional (2D) model for the microchannel was developed using ANSYS Academic research CFD 18.2 software package, and volume of fluid method was adopted to solve the model numerically. The results obtained are in good agreement with the experimental results. In this work, slug length, pressure drop and velocity variations inside the slugs were captured at several operating conditions. The effects of contact angle (0°–155°), fluid viscosity, and surface tension on two phase flow interaction parameters along with the effect of both gas and liquid superficial velocities are discussed in detail. For gas–liquid two phase flow velocities were ranging from 0.025 to 0.5 m s−1 and capillary number (Ca) from 6.96 × 10−4 to 1.39 × 10−2. One of the key objectives of this investigation was to study the occurrence and behaviour of liquid film around the slug units. In fact, liquid film formed at low capillary number (Ca) was very thin and observed only for fine meshing near wall of the channel.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Abadie T, Aubin J, Legendre D, Xuereb C (2012) Hydrodynamics of gas–liquid Taylor flow in rectangular microchannels. Microfluid Nanofluid 12:355–369. https://doi.org/10.1007/s10404-011-0880-8
Asadolahi AN, Gupta R, Fletcher DF, Haynes BS (2011) CFD approaches for the simulation of hydrodynamics and heat transfer in Taylor flow. Chem Eng Sci 66:5575–5584. https://doi.org/10.1016/j.ces.2011.07.047
Bandara T, Cheung SCP, Rosengarten G (2015) Slug flow heat transfer in microchannels: a numerical study. Comput Therm Sci Int J 7(1):81–92. https://doi.org/10.1615/ComputThermalScien.2015012281
Brackbill JU, Kothe DB, Zemach C (1992) A continuum method for modeling surface tension. J Comput Phys 100:335–354. https://doi.org/10.1016/0021-9991(92)90240-Y
Chandra AK, Kishor K, Mishra PK, Alam MS (2016) Numerical investigations of two-phase flows through enhanced microchannels. Chem Biochem Eng Q 30(2):149–159. https://doi.org/10.15255/CABEQ.2015.2289
Dessimoz AL, Cavin L, Renken A, Kiwi-Minsker L (2008) Liquid–liquid two-phase flow patterns and mass transfer characteristics in rectangular glass microreactors. Chem Eng Sci 63(16):4035–4044. https://doi.org/10.1016/j.ces.2008.05.005
Gunther A, Jensen KF (2006) Multiphase microfluidic: from flow characteristics to chemical and material synthesis. Lab Chip 6:1487–1503. https://doi.org/10.1039/B609851G
Guo F, Chen B (2009) Numerical study on Taylor bubble formation in a microchannel T-junction using volume of fluid (VOF) method. Microgravity Sci Technol 21(Suppl. 1):S51–S58. https://doi.org/10.1007/s12217-009-9146-4
Gupta R, Fletcher DF, Haynes BS (2009) On the CFD modelling of Taylor flow in microchannels. Chem Eng Sci 64:2941–2950. https://doi.org/10.1016/j.ces.2009.03.018
Kashid MN, Agar DW (2007) Hydrodynamics of liquid–liquid slug flow capillary micro-reactor: flow regimes, slug size and pressure drop. Chem Eng J 131:1–13. https://doi.org/10.1016/j.cej.2006.11.020
Kashid MN, Renken A, Kiwi-Minsker L (2010) CFD modelling of liquid–liquid multiphase microstructured reactor: slug flow generation. Chem Eng Res Des 88:362–368. https://doi.org/10.1016/j.cherd.2009.11.017
Kawahara A, Chung PMY, Kawaji M (2002) Investigation of two-phase flow pattern, void fraction and pressure drop in a microchannel. Int J Multiphase Flow 28:1411–1435. https://doi.org/10.1016/S0301-9322(02)00037-X
Kawahara A, Sadatomi M, Nei K, Matsuo H (2009) Experimental study on bubble velocity, void fraction and pressure drop for gas–liquid two-phase flow in a circular microchannel. Int J Heat Fluid Flow 30:831–841. https://doi.org/10.1016/j.ijheatfluidflow.2009.02.017
Kawahara A, Sadatomi M, Nei K, Matsuo H (2011) Characteristics of two-phase flows in a rectangular microchannel with a T-junction type gas-liquid mixer. Heat Transf Eng 32(7–8):585–594. https://doi.org/10.1080/01457632.2010.509752
Khan W, Chandra AK, Kishor K, Sachan S, Alam MS (2017) Hydrodynamics and simulation studies of liquid-liquid slug flow in micro-capillaries. In: International conference IEEE on advances in mechanical, industrial, automation and management systems (AMIAMS), pp 281–284. https://doi.org/10.1109/amiams.2017.8069225
Kishor K, Chandra AK, Khan W, Mishra PK, Alam MS (2017) Numerical study on bubble dynamics and two-phase frictional pressure drop of slug flow regime in adiabatic T-junction square microchannel. Chem Biochem Eng Q 31(3):275–291. https://doi.org/10.15255/CABEQ.2016.877
Liu D, Wang S (2011) Gas–liquid mass transfer in Taylor flow through circular capillaries. Ind Eng Chem Res 50:2323–2330. https://doi.org/10.1021/ie902055p
Padoin N, Souza AZD, Ropelato K, Soares C (2016) Numerical simulation of isothermal gas–liquid flow patterns in microchannels with varying wettability. Chem Eng Res Des 109:698–706. https://doi.org/10.1016/j.cherd.2016.03.027
Qian D, Lawal A (2006) Numerical study on gas and liquid slugs for Taylor flow in a T-junction microchannel. Chem Eng Sci 61:7609–7625. https://doi.org/10.1016/j.ces.2006.08.073
Santos RM, Kawaji M (2010) Numerical modeling and experimental investigation of gas–liquid slug formation in a microchannel T-junction. Int J Multiphase Flow. 36:314–323. https://doi.org/10.1016/j.ijmultiphaseflow.2009.11.009
Santos RM, Kawaji M (2012) Developments on wetting effects in microfluidic slug flow. Chem Eng Commun 199:1626–1641. https://doi.org/10.1080/00986445.2012.660712
Sobieszuk P, Cygański P, Pohorecki R (2010) Bubble lengths in the gas–liquid Taylor flow in microchannels. Chem Eng Res Des 88:263–269. https://doi.org/10.1016/j.cherd.2009.07.007
Taha T, Cui ZF (2004) Hydrodynamics of slug flow inside capillaries. Chem Eng Sci 59:1181–1190. https://doi.org/10.1016/j.ces.2003.10.025
Talimi V, Muzychka YS, Kocabiyik S (2013) Slug flow heat transfer in square microchannels. Int J Heat Mass Transf 62:752–760. https://doi.org/10.1016/j.ijheatmasstransfer.2013.03.035
Triplett KA, Ghiaasiaan SM, Abdel-Khalik SI, Sadowski DL (1999) Gas–liquid two phase flow in microchannel—part I: two-phase flow patterns. Int J Multiphase Flow 25:377–394. https://doi.org/10.1016/S0301-9322(98)00054-8
Van Steijn V, Kreutzer MT, Kleijn CR (2007) μ-PIV study of the formation of segmented flow in microfluidic T-junctions. Chem Eng Sci 62:7505–7514. https://doi.org/10.1016/j.ces.2007.08.068
Xu JH, Li SW, Wang YJ, Luo GS (2006) Controllable gas–liquid phase flow patterns and monodisperse microbubbles in a microfluidic T-junction device. Appl Phys Lett 88:133506. https://doi.org/10.1063/1.2189570
Acknowledgements
The authors are thankful to financial supports from the Ministry of Human Resource Development (MHRD), India and MNNIT Allahabad for providing necessary equipment, computing facilities and support to perform this study.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Khan, W., Chandra, A.K., Kishor, K. et al. Slug formation mechanism for air–water system in T-junction microchannel: a numerical investigation. Chem. Pap. 72, 2921–2932 (2018). https://doi.org/10.1007/s11696-018-0522-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11696-018-0522-7