Comparative analysis of gas–liquid flow in T-junction microchannels with different inlet orientations

Xiang Ling,Dongren Liu,Hao Peng

doi:10.1177/1687814016637329

Xiang Ling, Dongren Liu + Show 1 more

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https://doi.org/10.1177/1687814016637329

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Journal: Advances in Mechanical Engineering	Publication Date: Mar 1, 2016
Citations: 12	License type: cc-by

Affiliation: Nanjing Tech University

Abstract

In this study, a comparative analysis of two-phase flow in T-junction microchannels with different inlet orientations was carried out. Based on computational fluid dynamics and the volume-of-fluid model, bubble size, bubble velocities, and pressure distributions were analyzed. The numerical algorithm was validated with the experimental observations from former literatures; the results show that when the capillary number, Ca, is low, the length of gas and liquid slug in the symmetric T-junction is higher than that in the cross-flow T-junction. The effect of different forces acting on the slugs during the process of bubble formation was studied by investigating the velocity gradient and pressure distribution in the mixing zone. The result shows that the shear stress in cross-flow T-junction is over two times of that in T-junction with two symmetric inlets under the same operating conditions, which indicates that the size of bubble and liquid slug depends on the shear stress at low Ca number.

Highlights

Two-phase flow in T-junction has been studied experimentally and numerically by many researchers such as Santos and Kawaji,[1] Barreto et al.,[2] and Fu et al.[3]
The results indicate that dimensionless length DLg decreases as the capillary number Ca increases
Shear stress is much lower compared with surface tension and other forces acting around the tip, we think this difference of stress is the main reason for the discrepancy of bubble length in two types of microchannels under the same operating conditions

Summary

Introduction

Two-phase flow in T-junction has been studied experimentally and numerically by many researchers such as Santos and Kawaji,[1] Barreto et al.,[2] and Fu et al.[3]. The air volume fraction in cross-flow T-junction is shown in Figure 4(a) and (b), the gas and liquid velocities were set to ug = 0.31 m/s and ul = 0.33 m/s.

Results

Conclusion