Reflection of vortex rings at a water-air interface
Phys. Rev. Fluids 10, 074703 – Published 21 July, 2025
DOI: https://doi.org/10.1103/dg4m-hbts
Abstract
We experimentally investigate how vortex rings, generated and propagating within a water tank, interact with the water-air interface. Near-perfect reflections of these vortex rings occur when they approach the interface at a sufficiently large incident angle. To understand this interaction, we employ a vortex-sheet-vortex-pair model in numerical simulations, which captures the essential dynamics. Additionally, a simplified model based on the conservation of flux or momentum provides further insight into the mechanism behind the vortex-ring reflection. Through combined approaches—experimentation, numerical simulation, and detailed analysis—we gain a deeper understanding of how vortex rings interact with free boundaries.
