• high-viscosity oils
• critical flow regimes
• Benjamin bubble
• viscous flows

In the present work, the development of a short-cut model describing the viscosity effects on the dynamic of Benjamin bubble is presented.
Since different flow regimes were found both in experiments and in numerical simulations, the aim of this model is to obtain, both for the supercritical regime and the subcritical regime, the translational velocity of the bubble, the height of the bubble nose, the pressure upstream the bubble nose and bubble shape for different values both of kinematic viscosity and pipe radius.
A good match can ben seen from the comparison between model and numerical results.