2022 Annual Meeting
Resonance Induced Instabilities for Surface Tension Measurement
This work presents multiple possible techniques to measure interfacial tension and viscosity using resonance-induced instabilities. The first technique involves electrostatic induced resonance of fluid bilayers, while the second employs similar methods to induce resonance in levitated molten metal droplets. Here, AC electrostatic fields are imposed upon the system and interfacial patterns are excited as a signal of resonance-induced instability. The idea is to determine the critical voltage and patterns at the resonant state and then correlate this to interfacial tension and viscosity via theoretical models. The presented work addresses two hypotheses. First, electrostatic forced oscillations of each system result in resonant conditions. Second, a reduced gravity environment reduces the critical voltage allowing for excitation of higher order modes increasing the possibility for self-benchmarking capability and isolating the effects of interfacial tension. Ground experiments will be shown for the levitated metal system showing patterns at the onset and highlighting the potential for self-benchmarking thermophysical property measurement. Ground and reduced gravity experiments will be shown for a model two fluid system clearly showing patterns at the onset and the reduced voltage at microgravity. The comparison of ground and flight data will be presented along with key plans for extending to liquid metals.