The Growth of Bubbles in an Acoustic Field by Rectified Diffusion

Abstract

Rectified diffusion is a bubble growth phenomenon that occurs in acoustic fields. When subjected to a sound field (i.e., an oscillating pressure wave), a bubble of a suitable size range undergoes expansion and compression. During this bubble oscillation, the pressure within the bubble decreases as it expands and increases as it compresses. Consequently, gas and/or vapor diffuses in and out of the bubble due to the differences in pressure between the interior and exterior of the bubble. Several effects contribute to an unequal diffusion in and out of the bubble. The "area effect" refers to the influence of surface area on the mass diffusion. More gas tends to enter the bubble during bubble ex..