Physically Realistic Models of Catastrophic Bubble Collapses

Abstract

When gas micro-bubbles are forced with an acoustic field they typically undergo a slow expansion followed by a violent collapse. During the expansion phase a significant amount of vapor enters the bubble. While much of this vapor is expelled as the bubble collapses, significant excess vapor is trapped in the interior during this violent collapse. As the bubble collapses this vapor is significantly heated and undergoes dissociative chemical reactions. Applications which take advantage of these acoustically driven chemical reactions are generally known as sonochemistry. Using the results of direct numerical simulations as a base, reduced models of the transport and gas dynamics of this sonochemical process are carefully developed. The models are compared to experimental data, showing that the reduced formulations can be used to predict real phenomena.