The present study has been carried out to investigate the characterization of two-phase flow bubbles that occurred in a column of an internal diameter 50 mm, where the liquid phase is represented in Silicone oil. The effectiveness of the tomography technique regarding the flow patterns analysis is studied as well as, high-speed videos were captured and used in the study. The void fractions of the time series were obtained at different flow rates were considered, and the results were analyzed also by using Probability Density Functions (PDF), film thickness, velocity structure, and Power Spectrum Density (PSD). To obtain the structure velocity, two tomography capacitance sensors were utilized so as to do cross-correlation, besides, the obtained videos were considered also to show the different bubble characteristics. A comparison was assessed between the previously available works of literature with the present study to evaluate the results. It was observed from the obtained tomography images that the flow was in the slug flow region explained by the presence of large bullet-shaped bubbles and the bubble characteristics obtained were comparable to that observed in other viscous liquids. Electrical Capacitance Tomography (ECT) was quite effective in investigating the flow.
