Cavitation bubble dynamics and sonochemiluminescence activity inside sonicated submerged flow tubes
Abstract
Bubble dynamics and luminol emissions of cavitation in sub-millimeter-sized PFA flow tubes, submerged in an ultrasonic bath reactor, are studied at 27 kHz driving frequency. Nucleation of cavitation inside the tubes only takes place via a free interface, realized here in form of an alternating water-air slug flow. High-speed recordings show that cavitation bubbles in the water slugs often develop localized structures in form of clusters or bubble plugs, and that such structures can be seeded via a single pinch-off from the free interface. Within the structures, bubbles strongly interact and frequently undergo merging or splitting events. Due to the mutual interaction and resulting motion, bubbles often collapse with a fast displacement, suggesting jetting dynamics. Bubble compression ratios are estimated on basis of observed individual bubble dynamics and numerical fitting by a single bubble model. The resulting peak temperatures around 3000 K allow for dissociation of water vapor. This is in accordance with observed sonochemiluminescence from luminol, originating from active bubble zones in the tubes.
Cite
@article{arxiv.2011.14797,
title = {Cavitation bubble dynamics and sonochemiluminescence activity inside sonicated submerged flow tubes},
author = {Busra Ekim Sarac and Dwayne Savio Stephens and Julian Eisener and Juan Manuel Rosselló and Robert Mettin},
journal= {arXiv preprint arXiv:2011.14797},
year = {2020}
}
Comments
23 pages, 7 figures