Motion of large gas bubbles through liquids in vertical concentric and eccentric annuliMotion of large gas bubbles through liquids in vertical concentric and eccentric annuli Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2015-10-291990enTaylor bubbles rising through liquids in vertical circular tubes and between parallel planes are axisymmetric and nearly spherical at the top. In a vertical annulus, however, the bubbles are radially asymmetric and never occupy the whole cross-sectional area. Analysis indicates that axisymmetric bubbles rise in an annulus at lower rates than those observed experimentally and hence are never observed in practice. In contrast, the asymmetric bubbles take an elliptic shape which results in higher rise velocities. A theoretical model for the rise velocity of an elliptic bubble has been developed and the comparison with experiment is satisfactory.Δημοσίευση σε επιστημονικό περιοδικό http://creativecommons.org/licenses/by/4.0/International Journal of Multiphase Flow316 375–390 Kelesidis Vasilis Κελεσιδης Βασιλειος Dukler A.E. Elsevier Taylor bubbles annulus rise velocity