Three-dimensional bubble jetting inside a corner formed by rigid curved plates: Boundary integral analysis

Three-dimensional dynamics of a transient bubble inside a corner formed by two rigid curved parabolic plates (walls) is studied numerically using boundary integral method (BIM) based on the potential flow theory. The bubble dynamics, including the expansion and collapse phases until the jet impact, are investigated for different corner angles associated with different focal lengths k of the parabolas. However, for all the simulations, the dimensionless initial vertical standoff distance of the bubble's center from the corner edge (h*) is fixed at 4. The bubble remains almost spherical during expansion, except for parts of its surface that flattens near the walls. When the bubble is initiated at the bisector plane of the two intersecting walls, it oscillates symmetrically with respect to the bisector plane and becomes oblate during the late stages of the collapse phase. A high-speed liquid jet forms towards the end of bubble collapse, pointing to the corner. If the corner angle decreases, the bubble becomes more oblate along the bisector plane making the ensuing liquid jet wider and slower. In addition, a bubble initiated closer to one of the two walls is mainly influenced by the closer wall, oscillates non-symmetrically with respect to the bisector plane and the liquid jet formed in this case is inclined towards the closer wall due to the greater Bjerknes force of that wall.