Study of unsteady gas-liquid two-phase flow induced force fluctuation (Part 2: Horizontal-downward two-phase flow)

Abstract

This study aims to investigate the horizontally oriented internal two-phase flow induced force fluctuations. Gas-liquid two-phase flow experiments were conducted on 90 degree pipe bend, oriented horizontal-downwardly. Multiple tri-axial force transducers were utilized to measure the dynamic force signals, and related two-phase flow parameters such as volumetric fluxes, void fraction and local pressure fluctuations were measured at various horizontal two-phase flow regimes. Unlike upward two-phase flow, horizontal-downward elbow orientation significantly altered the two-phase flow structure. Spectrum analysis was conducted to investigate the linkage between two-phase flow characteristics and force fluctuation. Results show that the predominant frequency of the fluid force peaks in the slug flow regime at a constant liquid flow rate, similar to the upward two-phase flow condition. Based on the database developed in the current experiment, previously developed force fluctuation model was utilized to assess its performance, and it was found that the model is capable of predicting these parameters with satisfactory accuracy.