Collapse dynamics of bubble pairs in gelatinous fluids

In this study, we present a novel experimental setup that uses a shock tube and applies a gelatinous mixture as a water-like carrier medium. Millimeter-sized air bubbles, placed in the gelatin and exposed to an instantaneous pressure increase, are analyzed under two different aspects. First, we show that single bubbles in the gelatin behave very similarly to bubbles in water during the collapse and that different gelatin concentrations do not significantly affect the behavior. In a second part, we study interacting bubble pairs and differentiate four main types of interaction that can also be characterized by non-dimensional parameters. A well-known type, jetting towards each other, is reproduced and a type termed ‘reversing collapse’ shows similarities to previous work as well as new aspects. The interaction of bubbles of large size ratios is either dominated by the large bubble if bubbles are far apart or leads to a pronounced liquid jet if the bubbles are close to each other. This dataset provides additional related material for the interested reader. Image and videos of the experiments visualize the involved dynamic processes and provide a reference for future work. In addition, exact figure data are provided in Matlab figures and tables as reference and for further use.