Study of liquid–gas two-phase flow in horizontal pipes using high speed filming and computational fluid dynamics

•Monitoring, measuring and analyzing multiphase flow significant characteristics (void fraction, flow pattern).•CFD methodology for different flow pattern in horizontal pipes.•Executable tool with different high image analysis alternatives that enabled the correct analysis for different flow pattern. A study of liquid–gas two-phase flow in short horizontal pipes was carried out experimentally using a High Speed Filming (HSF) Analysis and numerical simulations. In the experiments, the flow pattern was determined and HSF were recorded for six experimental cases. Those films were analyzed using an image analysis tool that was developed, and, consequently, the void fraction as a function of time was obtained. Numerical simulations of the two-phase mixture inside the pipe were carried out with a commercial CFD software, using the Volume of Fluid (VOF) method. The void fraction and the flow pattern were thus determined. The results of the numerical simulations were compared in terms of flow pattern with the experimental data and in terms of void fraction with the HSF analysis. A good agreement was found in both cases, especially for annular and slug flow patterns.