Numerical Simulation of Gas-LiquId Flow in a Horizontal Elbow

Gas-liquid flow (GLF), especially slug and annular flows in oil and gas gathering and transportation pipelines, become particularly complex inside elbows and can easily exacerbate pipeline corrosion and damage. In this study, FLUENT was used to conduct 3D simulations of slug and annular flow in elbows for different velocities to assess the ensuing changes in terms of pressure. In particular, the multifluid VOF (Volume of Fraction) model was chosen. The results indicate that under both slug and annular flow conditions, the pressure inside the elbow is lower than the outside. As the superficial velocity of liquid and gas increase, the pressure and liquid flow velocity at different positions of the elbow also increase, while the secondary flow weakens. Under annular flow conditions, the liquid film on the outer side of the elbow is thicker than that on the inner side, and the liquid velocity in the main liquid film zone is the lowest.