Two-phase gas-liquid flow in conditions of expansion and contraction of channel

The paper presents the results of studies concerning the effects of sudden change of cross-sectional area on the flow patterns and local pressure losses in the horizontal flow of two-phase mixture. The scope of research include the observation of flow patterns of flowing mixture and their disturbances caused sudden change in cross-section of the pipeline. In addition, flow resistance affecting pressure change before and after the local obstacle were measured. The experiment was conducted in a horizontal flow through the measuring channel with a local obstacle in the form of a sudden change in channel cross-sectional area. Measurement channel was a system of two interconnected tubes with internal diameters of 40 and 22 mm and a total length of 7 m. The air, water and oil were used in the experiments. Analysis of the experimental data leads to the conclusion that the mathematical model for calculating the two-phase flow pattern disturbance areas and their impact on the value of the pressure drop in the pipe with a sudden expansion and contraction should take into account both the parameters of the liquid phase and gas phase.