Bubble levitation and translation under single-bubble sonoluminescence conditions.
Bubble levitation in an acoustic standing wave is re-examined for conditions relevant to single-bubble sonoluminescence. Unlike a previous examination [Matula et al., J. Acoust. Soc. Am. 102, 1522-1527 (1997)], the stable parameter space [Pa,R0] is accounted for in this realization. Forces such as the added mass force and drag are included, and the results are compared with a simple force balance that equates the Bjerknes force to the buoyancy force. Under normal sonoluminescence conditions, the comparison is quite favorable. A more complete accounting of the forces shows that a stably levitated bubble does undergo periodic translational motion. The asymmetries associated with translational motion are hypothesized to generate instabilities in the spherical shape of the bubble. A reduction in gravity results in reduced translational motion. It is hypothesized that such conditions may lead to increased light output from sonoluminescing bubbles.
Matula
Thomas J
TJ
Applied Physics Laboratory, University of Washington, 1013 NE 40th Street, Seattle, Washington 98105, USA. matula@apl.washington.edu
D000162:Acoustics; D049449:Luminescence; D008962:Models, Theoretical; D013997:Time Factors