Dynamics of a single bubble collapse near a complex wall–ice boundary

This study investigates the fundamental dynamics of a single pulsating bubble collapsing in the complex corner geometry formed by a rigid wall and an adjacent ice plate. Coupled experiments using spark-induced bubbles under various ice thicknesses and wall–ice angles were conducted and complemented by Arbitrary Lagrangian–Eulerian numerical simulations, which were validated with deviations below 10%. The results reveal a rich variety of jetting phenomena governed by the interplay between the wall–ice angle and the dynamic state of the ice boundary. We have identified and categorized four distinct and repeatable jetting modes: Fracture-redirected Jet (FRJ), bisector jet, divergent jet, and split jet (SJ). These modes are shown to be a direct consequence of the initial boundary geometry. For example, ice fracture dynamically changes the boundary from rigid to a free surface, redirecting the jet (FRJ), while a small gap at the wall–ice interface can trigger bubble fission (SJ). The resulting ice fracture patterns and structural pressure footprints serve as clear physical manifestations of these distinct fluid dynamic modes. This work establishes a direct link from initial geometric conditions to the resulting bubble jet dynamics, providing a fundamental understanding of bubble collapse in confined, complex environments.