### ASA 125th Meeting Ottawa 1993 May

## 4pPA7. The radial oscillations of a gas bubble in a surfactant solution.

**Yuren Tian
**

**
Xiaoyu Zheng
**

**
Glynn Holt
**

**
Robert E. Apfel
**

**
**
*Ctr. for Ultrason. and Sonics, Yale Univ., 2159 Yale Station, New Haven,
CT 06520
*

*
*
In a surfactant solution, a gas bubble can be covered by an adsorbed film
of surfactant. When the bubble is excited into radial oscillations by a sound
field, the surface concentration of the surfactant varies with the surface area
and the mass interchange between the surface and the bulk liquid. As a result,
the surface tension becomes a function of the bubble radius. Previous
theoretical work on this subject [R. E. Glazman, J. Acoust. Soc. Am. 74,
980--986 (1983)] will be commented on and the equations governing the radial
oscillations for this kind of gas bubble will be discussed. By numerically
solving the equation under different initial bubble sizes, sound pressures, and
driving frequencies, one can determine the effects of variable surface tension,
surface viscosity, and surface mass transfer on the motions of the gas bubble.
Thresholds of transient cavitation will also be estimated by including these
effects. [Work supported by NASA through JPL, Contract No. 958722.]