78th Annual Meeting of the APS Division of Fluid Dynamics (Nov 23 — 25, 2025)

V014: Wavy water entry: it's just a phase

Air-water entry is a classical problem in fluid mechanics, however most prior studies neglect any role of an unsteady interface, anticipated to be relevant in most practical scenarios. In this work, we introduce an axisymmetric wavefield to a classic water entry experiment, demonstrating that interfacial disturbances can have a dramatic influence on splash-dome formation and resultant air entrainment. In particular, we drop small superhydrophobic spheres onto a controlled standing wavefield, generated by a heaving ring driven at the air-water interface. By varying the wave phase at impact, we show that striking a wave crest can geometrically disrupt splash-dome formation, thereby extending entrainment. In contrast, striking a trough can accelerate splash-dome closure and prematurely limit entrainment. Increasing the wave amplitude can amplify phase-dependent effects, overall suggesting that waves may be important to consider in practice while providing us with a new method for controlling splash-dome formation and air entertainment.