Study on the Hydrodynamic Performance and Stability Characteristics of Oil-Water Annular Flow through a 90° Elbow Pipe

The transportation of highly viscous oil surrounded by water annulus has been recognized as a feasible option in terms low-energy consumption and high efficiency. During the process heavy delivery, problem pipe fittings is inevitably encountered, most common one elbow assembly. In this present study, simulations for oil-water core annular flow (CAF) through 90° were performed computational fluid dynamics (CFD) based on VOF, standard k-ε, CSF models. Simulation results consistent with experimental data, which verifies validity practicability proposed model. effects inlet fraction, superficial velocities water, properties (density viscosity), geometry-related parameters (diameter ratio, wall roughness, surface wettability) hydrodynamic performance stability characteristics explored. It revealed that properties, geometric do influence volume fraction ring. Furthermore, may adhere to downstream under certain operational conditions. could provide reference design structures optimization operation parameters.