... is compared with downward flow in pipes. The comparison results show some differences between downward two-phase flow in annulus and pipes for the liquid holdup and flow regimes. This comparison shows a significant disagreement between flow in annulus and pipes for a wide range of conditions...

... and modelling studies on gas-liquid two-phase flow have been carried out owing to its importance in industrial applications. In petroleum industry, relatively few investigations in vertical downward two-phase flow have been reported as compared with horizontal and vertical upward. Downward flow has been...

... to gravity forces. As a result, higher liquid velocities are required to have a transition from stratified to non-stratified. test section stratified flow downward flow bhr group 2012 liquid viscosity production logging inclination angle gas velocity criterion university of tulsa reservoir...