Detection and analysis of transition from annular to intermittent flow in vertical tubes

Authors

  • Ramkrishna Das,

    1. Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur-721302, India
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  • S. Pattanayak

    Corresponding author
    1. Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur-721302, India
    • Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur-721302, India
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Abstract

In vertical co-current gas-liquid flow, the transition from annular to intermittent flow occurs when gas core becomes interrupted by liquid bridges due to the instability of the interfacial capillary waves. An analytical model is formulated to explain the liquid bridging in terms of the growth of finite amplitude interfacial capillary waves. Experimental results show that the longest wave length, which is associated with the transition, is about eight times the wave length of waves moving with the velocity of the liquid film.

Abstract

Dans l'écoulement gaz-liquide à cocourant vertical, la transition entre les écoulements annulaire et intermittent survient lorsque le noyau de gaz est interrompu par des ponts liquides dus à l'instabilité des ondes capillaires interfaciales. On a formulé un modèle analytique afin d'expliquer le «pontage» en termes de croissance des ondes capillaires interfaciales d'amplitude finie. Les résultats expérimentaux montrent que la longueur d'ondes la plus grande associée à la transition représente huit fois la longueur des ondes que se déplacent avec la vitesse du film liquide.

Ancillary