Characterization of Gas‐Liquid Two‐Phase Flows Using Laser Patterns

Abstract

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 4.7 mm and 3.4 mm 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.