THE IMPLEMENTATION OF IMAGE PROCESSING TECHNIQUE TO DETERMINE THE INTERFACIAL BEHAVIOR OF GAS-LIQUID WAVY TWO-PHASE FLOW IN A HORIZONTAL PIPE

An experiment has recently been conducted to study the flow behavior of stratified gas-liquid two-phase flow in a horizontal pipe. It was aimed to determine the interfacial behavior of stratified gas-liquid two-phase flow, and also, developed a high quality database of it. The longitudinal section of transparent acrylic horizontal pipe (26 mm i.d.) was used as the reference section of image recording. Air and water were used as the test fluids, flowing cocurrently inside the pipe. To ensure the flow become stratified two-phase flow, a separated inlet by a flat plate was used in the mixing section. The flow behavior was recorded by using a high speed video camera around 5 m in axial distance from the inlet pipe to ensure the fully-developed stratified gas-liquid two-phase flow. To correct the refraction due to the acrylic pipe, correction box was used in the visualization test section. The group of stratified smooth, stratified ripple, stratified roll, and pseudo-slug were successfully recorded and classified based on the visualization study from 24 couples of the test condition of water superficial velocity and air superficial velocity. The recorded images were digitized on a computer. Digital image processing techniques were then used to perform quantitative analysis and the results were used to evaluate the existing data. In this study, image processing technique was performed to obtain and plot data of liquid hold-up distribution, power spectral density, cross correlation and probability distribution function of a liquid hold-up of the flow. From these result, the behavior of stratified smooth and stratified wavy two-phase flow was discussed. Based on the power spectral density analysis, it was found that, the wave frequency increases as the water superficial velocity increases, meanwhile, the air superficial velocity does not play an important role on the wave frequency