Wesley L. Nyborg
Dept. of Phys., Univ. of Vermont, Burlington, VT 05405
When surface waves occur on the boundary of a gas-filled space surrounded by liquid, the resulting motions of the gas include velocity components parallel to the gas--liquid interface. Because these satisfy a nearly nonslip condition, boundary layers are established and small-scale acoustic streaming is generated in the gas phase. Approximate theory suggests that significant convection can occur, and may play a role in sonic enhancement of rate processes which occur at gas--liquid interfaces. For example, intrabubble streaming may contribute to the enhancement of rectified diffusion observed by Gould [J. Acoust. Soc. Am. 56, 1740--1746 (1974)].