Thin liquid film method for analyzing gas-liquid annular flow in nonstraight pipe components

This study employs the thin liquid film method (TLFM) to analyze annular flow in nonstraight pipe components. The TLFM considers the interaction among the liquid film, gas phase, and droplets and requires a specific numerical method for implementation. Following thorough verification against experimental results from straight pipelines, the TLFM is applied to investigate the evolution of annular flow in a U-bend, a 90-degree bend, and a T-junction. In bends, the flow field morphology is dominated by two symmetrical cyclones generated by the gas phase. In the T-junction, gravity significantly influences annular flow formation in the main branch, while the gas cyclone causes redistribution of the liquid phase within the liquid film in the side branch.