Cyclic liquid-jet behavior in pulsating bubbles

Abstract

Motion pictures will be shown of liquid jets that develop in air bubbles pulsating at 60 Hz and redevelop in each cycle. The air bubbles grow by rectified diffusion from nuclei present in a glycerin-water mixture to sizes on the order of a few millimeters, and are then trapped on a platform situated within the resonator. The resonator consists of an aluminum cylinder, with heavy glass end windows, that is oscillated at 60 Hz by a vibration platform. The ambient pressure above the liquid is reduced to near that of the vapor pressure, which allows the resonator to generate large pulsation amplitudes in the air bubbles at low driving amplitudes. The pictures to be shown were made in two different ways. The first was made with a high-speed Fastax camera running at approximately 4000 frames/sec with bright field illumination. The second was made with bright field illumination from a high-intensity strobe that was driven near the oscillation frequency of the resonator. [Work supported by the Naval Academy Research Council and the Office of Naval Research.]