1. Equilibrium Taylor bubble in a narrow vertical tube with constriction
- Author
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(0009-0005-6633-0656) Maestri, R., (0009-0000-8275-8429) Radhakrishnakumar, S., Bürkle, F., (0000-0002-4764-7827) Ding, W., Büttner, L., Czarske, J., (0000-0002-7371-0148) Hampel, U., (0000-0003-0540-3426) Lecrivain, G., (0009-0005-6633-0656) Maestri, R., (0009-0000-8275-8429) Radhakrishnakumar, S., Bürkle, F., (0000-0002-4764-7827) Ding, W., Büttner, L., Czarske, J., (0000-0002-7371-0148) Hampel, U., and (0000-0003-0540-3426) Lecrivain, G.
- Abstract
Air Taylor bubbles in a millichannel filled with water are characterized by an elongated shape, a bullet-shaped nose and a comparatively flat tail. Many experimental and numerical investigations have been performed in the past. Yet, most of them consider Taylor bubbles in a straight channel with constant cross-section. The effect of a local change in the channel geometry on both the bubble shape and the flow fields on each side of the gas-liquid interface is, however, difficult to predict. In this work, we present experimental data obtained in a vertical millichannel, where the flow is moderately obstructed by a constriction, whose ratio ranges from 10 to 36 %. \rhandrey{We find that the Taylor bubble takes an equilibrium position for downward liquid flow with 264.36 < Re < 529.67 and 264.36 < Re < 728.29 for 10.17 % and 18.06 % constriction ratios, respectively}. In this area, an empirical correlation characterizing the bubble head is provided. Other flow regimes, such as bubble breakup, co- and counter-current configurations are identified and shown in the form of a regime map. The results, besides their relevance in process engineering, exhibit high reproducibility and will serve as reference for future interface resolving two-phase flow simulations.
- Published
- 2024