### ASA 127th Meeting M.I.T. 1994 June 6-10

## 4aPA3. Resonance effects in axisymmetrically forced bubble oscillations.

**R. Glynn Holt
**

**
Eugene H. Trinh
**

**
**
*Microgravity Res. Group, MS 183-401, Jet Propulsion Lab., 4800 Oak Grove
Dr., Pasadena, CA 91109
*

*
*
Large (0.02(less than or equal to)kR(less than or equal to)0.5) bubbles
are levitated in a primary acoustic field, trapped slightly above the pressure
nodes. A secondary, amplitude-modulated acoustic field is superimposed to
directly force the axisymmetric shape modes at a variety of pressures and
frequencies. By satisfying the condition for external resonance (when the
external modulation frequency f[sub d] is nearly equal to one of the
mode-number-dependent shape oscillation frequencies f[sub n], n=2,3,4,...) the
possibility of coupling energy into the volume mode via internal resonance
(when the volume mode frequency f[sub 0] is nearly an integral multiple of
f[sub n]) is investigated. In particular, the viability for such an experiment
in 1g at reduced ambient pressures is discussed. Finally, the possibility for
performing such an experiment in 0g is discussed. [Work supported by NASA.]