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The generation of secondary vortices from a wall-bounded vorticity sheet is a frequent occurrence in vortex ring–structure interactions. Such interactions arise in both engineering and biomedical applications, including tracheoesophageal speech. This study investigated the evolution of secondary vorticity following impact of an axisymmetric vortex ring on a concave hemicylindrical cavity. A primary vortex ring (PVR) with a formation number of F=2.00 and Reynolds number of ReΓ=1500 was generated within a water tank. Five different ratios of hemicylindrical cavity radius (Rcyl) to PVR radius (Rv) were examined; namely, γ=4,  3,  212,  2, and 112. Flow visualization and particle image velocimetry analysis of the scenarios revealed the asymmetric impact of the PVR on the cavity surface. This asymmetric impact leads to distinctive flow dynamics in the evolution of secondary vorticity across both the transverse and longitudinal planes. In the transverse plane, the PVR impact generated a secondary vortex ring (SVR) and a tertiary vortex ring (TVR). Following generation, the SVR and TVR rotated completely around the PVR. In the longitudinal plane, the SVR produced a horseshoe-like loop instead of rotating around the PVR completely. For γ=4,  3, and 212, the SVR loop moved upward due to self-induction. For γ=2 and  112, the legs of the SVR horseshoe-like loop experienced reconnection and produced two new vortex rings. The upward trajectory of the SVR horseshoe-like loop varied with γ, tending to move further from the primary ring's axis as γ decreased. 

Flow-induced vibrations of flexible surfaces driven by coherent vortical structures are ubiquitous in engineering and biological flows; from the extraction of fluidic energy via oscillating electro-active polymers to vocal fold dynamics during voiced speech production. These scenarios may involve either discrete or periodic loading conditions due to the advection of vortices past the structure. This work considers, as a function of the vortex production frequency, the fluid-structure interaction that occurs as vortices are propagated tangentially over flexible plates with variable structural properties. Velocity fields are acquired with particle image velocimetry and used to compute the vorticity and pressure fields, while the plate energy is estimated from its kinematics. Primary and secondary peaks in plate deflection amplitude and the plate energy as a function of vortex production frequency are observed at integer fractions of the fundamental plate frequency. At resonance conditions, plate energy relative to discrete vortex loading is increased by approximately three orders of magnitude, while the sub-harmonics increase the plate energy by about two orders of magnitude. Additional physical influences on the energy exchange process, including vortex-to-plate spacing and Strouhal number, are also investigated, detailing the importance of spatial and temporal interactions. The magnitude of the initial plate deflection as the vortex ring approaches the plate, due to persistent vibrations from previous interactions, is shown to retard the time at which the maximum load is applied as the increased relative vortex-to-plate spacing weakens cross-sign vorticity interactions. Finally, plate properties are scaled to model the structural properties of the vocal folds and the effect of intra-glottal vortices on vocal fold dynamics is quantified, where a negligible influence is observed.