Numerical investigation of the collapse of a static bubble at the free surface in the presence of neighbors

The present study numerically investigates the bubble-bursting phenomenon at the free surface under the influence of symmetric and asymmetric patterns of neighboring bubbles. To conduct the simulation, a static pierced bubble at the interface of liquid and gas has been used and neighboring unpierced bubbles are added, if necessary. In the presence of symmetric neighbors, fluidic stages of the bursting process are established as cavity collapse, jet formation, and consequential fragmentation of the jet into drops. A thorough comparison of bubble bursting with symmetric neighbors (BBSN) and similar bursting of a solitary bubble (BSB) has been shown. Bubble bursting under the influence of an asymmetric pattern is compared with BBSN. Bubble with absent neighbors (BWAN) placement turns into the formation of the bent jet which is lying in the plane of the angular bisector of the absent neighbors. Bending of the jet nullifies as time progresses and turns into a vertical one like the jet dynamics observed in BBSN. A simple pictorial understanding has been presented to describe the reason behind the jet bend in BWAN based on a study of velocity vectors and the gap between the collapsing waves. The effect of a number of absent neighbors is also addressed extensively. As the number of absent neighbors increases, eventually, the jet inclination angle first increases and then decreases to match with the observation of BBSN and BSB. Finally, physical insight behind the rich fluidic phenomenon of the bubble bursting under the influence of different surface tensions and bubble sizes in the same cluster is also addressed.