Mathematical Modeling of Gas-Liquid Flow Patterns in an Annular Space with a Rotating Inner Cylinder

Gas-liquid flow patterns were mathematically modeled in the annular space between two coaxial cylinders, the inner cylinder of which rotates about its axis at a constant speed and the outer cylinder is at rest. The mathematical model was based on the fundamental laws of conservation of mass and momentum. The position of the mobile liquid-gas interface was tracked with the volume-of-fluid method. Two different flow patterns were detected: a stratified flow and a flow in which the gas phase is localized along a helix near the surface of the inner cylinder. The dependences of the dimensional torque on the axial and azimuthal Reynolds numbers were presented.