Understanding bubble-cylinder interactions: Experimental insights into cutting dynamics and liquid film evolution

Bubble cutting in the interaction with an obstacle is a phenomenon in many industrial applications, such as slurry bubble columns. These columns are widely utilized in industry due to their efficient mass and heat transfer capability. Understanding bubble behavior in the interaction with solid particles or internal structure becomes essential for designing and optimizing these reactors. As such, in this study, the interaction of a single rising bubble with a fixed cylindrical obstacle is investigated as a small-scale representation of these interactions inside the column. Two distinct interaction regimes based on the interface breakage are identified: a no-cutting regime, where the bubble bypasses the obstacle without breakage, and a cutting regime, where the bubble breaks. The transition between these regimes is mapped using the Reynolds number and modified Eötvös number to capture the influence of inertial, viscous, and surface tension forces. In addition, the formation and dynamic of the liquid film between the bubble and cylinder are studied. Results show that the minimum liquid film thickness is proportional to the Capillary number and bubble-to-cylinder size ratio. Based on these parameters, a predictive model is developed to estimate the minimum liquid film thickness. These results provide fundamental insights into the bubble-structure interactions, offering a basis for developing scale-up numerical models for the real-sized three-phase bubble columns.