Low-Gravity Dynamics of Vortical Interfaces and Sloshing in an Axisymmetric Tank

In contrast to traditional liquid-gas separators, vortical flows offer a simple, power-efficient architecture that relies only on input momentum to separate gas from liquid via the centripetal buoyant force. The integrity of the gas core is critical for the separator function, as modal oscillations of too great a magnitude would lead to an ingestion of bubbles in the liquid outlet or liquid in the gas outlet. Despite its relevance to advancing the technology, the forced-oscillation dynamical response of the gas-liquid interface remains unstudied for vortical flows. To address this gap, the Vortical Interfaces and Sloshing in Axisymmetric Tanks (VISAT) experiment studies the interfacial response of a low-gravity vortex to forced oscillations. Inertial and visual data are collected across seven low-gravity parabolas, interfacial edge detection is performed, and analysis via Fast Fourier Transforms reveals the system eigenfrequencies for each spin-perturbation pair. Results from three parabolas are presented here, where for the 3.2 Hz rotation rate, the 1.5 Hz perturbation frequency yields antisymmetric modes at 1.3 and 5.1 Hz. For the same rotation rate, the 3.5 Hz perturbations result in spectrally distinct peaks at 3.1, 6.4, and 9.6 Hz and higher, with increasing nodal counts.