This paper investigates the capability of the two-fluid model to predict the bubble drift velocity of elongated bubbles in channels. The two-fluid model is widely used in the oil and gas industry for dynamic multiphase pipeline simulations. The bubble drift velocity is an important quantity in predicting pipeline flushing and slug flow. In this paper, it is shown that the two-fluid model in its standard form predicts a bubble drift velocity of (similar to the shallow water equations), instead of the exact value of as derived by Benjamin[1OpenURL Universiteit Twente]. Modifying the two-fluid model with the commonly employed momentum correction parameter leads to a steady solution (in a moving reference frame), but still predicts an erroneous bubble drift velocity. To get the correct bubble drift velocity, it is necessary to include the pressure variation along the channel height due to both the hydrostatic component and the vertical momentum flux.
Sanderse, B., Haspels, M., & Henkes, R. A. W. M. (2015). Simulation of Elongated Bubbles in a Channel using the Two-Fluid Model. Journal of dispersion science and technology, 36(10), 1407-1418. https://doi.org/10.1080/01932691.2014.989571