(168a) 3D Vof Simulation of Intermittent Flows in Inclined Pipes

Slug flow is one of the most predominant and unwanted flow pattern in multiphase oil and gas pipelines, severe slugging knocks off the separation systems. Accurate prediction of slug formation and slugging frequency leads to a better design and operation of oil and gas separation units. The multi-dimensional nature of fluid dynamic process that characterises slug flow as well as its transient nature, has made it more difficult to fully understand. However, recent advances in computational power has made Computational Fluid Dynamics (CFD) one of the key tools for investigating intricate flow behaviour. In this research, The Volume of Fluid (VOF) model of ANSYS Fluent was used to carry out a set of simulation runs with different liquids and gases in three different pipes with internal diameters of 20, 40, and 60 mm, across a superficial velocity ranges of 0 to 2 m/s for the liquid phase and also 0 to 20 m/s for the gas phase. To study the combined effects of viscosity, velocity and inclination angle, five different pipe orientations was investigated; 30 degrees upward inclined, 15 degrees upward inclined, horizontal pipe, 15 degrees downward inclined, and 30 degrees downward inclined. Some of the simulation runs are verified experimentally, and there is a good agreement between the simulation output and experimental results.