Measurement of Three-Dimensional Characteristics of Slug Flow

Gas-liquid slug flow in horizontal pipes occurs frequently in industrial applications and is harmful to the piping systems owing to its intermittent structures. Therefore, it is essential to accurately describe the flow structure and investigate the flow mechanism. A non-intrusive fluorescence imaging method is employed to quantitatively reconstruct the slug bubble in a 15mm ID horizontal pipe in this article. Optical distortion correction method is firstly developed to improve the measurement accuracy of the instantaneous gas holdup, and then the time-average axial bubble velocity is simultaneously measured according to the feature matching of cross-sectional images. Additionally, the influence of phase superficial velocity on the interface stability is investigated through the phase holdup and the circumferential curvature distribution analysis. The typical three-dimensional structures of slug bubble are finally reconstructed through the velocity-based bicubic interpolation and median fusion algorithm. Previous correlations and reference instrumentation are used to evaluate the proposed method. Comparison results show that the method can effectively measure the flow parameters and reconstruct slug bubbles.