Canadian Journal of Chemical Engineering, Vol.93, No.9, 1678-1685, 2015
Characterization of Gas-Liquid Two-Phase Flows Using Laser Patterns
Two-phase flows play a vital role in refrigeration, air conditioning, and other industrial applications. This necessitates the development of precise techniques to characterize various two-phase flow regimes. In the present work, characterization of two-phase flow in horizontal tubes of diameters 4.7mm and 3.4mm is done by analyzing laser patterns. Laser patterns are recorded using a high-speed camera. The area occupied by laser patterns for air-water and air-oil flows is analyzed by applying grayscale analysis and distance transformation techniques in image processing. A technique based on the movement of the centre of intensity of the laser pattern is used to characterize two-phase flow regimes. Centre of intensity of a laser pattern is the point with maximum pixel intensity in the processed image. Probability density estimation together with the position-time graph for centre of intensity is used to characterize two-phase flow patterns. Bubbly, slug, and stratified flow regimes are observed and analyzed. The slug length and velocity is calculated by analyzing laser patterns. The two-phase flow regime map is generated based on the identified two-phase flow patterns and is validated with a flow map for conventional channels available in the literature.