Dynamical response of a bubble submitted to two following shock waves

Abstract

A numerical study of the dynamical response of a bubble submitted to two following shock waves is reported. After the passage of a shock wave, a micron-size bubble expands enormously, reaching millimeter size, and then inertially collapses; this is the so-called cavitation phenomenon. The influence of the passage of a second shock wave on the bubble inertial collapse control is investigated. This control may have a considerable impact for drug delivery or gene transfer, by the use of extracorporeal shock wave lithotripsy, which is a technique already used in medical treatment for kidney stones. It is shown that the dynamical response of the bubble qualitatively depends strongly on the forcing shape. Furthermore, for a given forcing shape, the dynamical response depends on both the delay and forcing amplitude ratio between the two applied shock waves. [This work has been done in collaboration with Ruediger Toegel, Claus-Dieter Ohl, and Detlef Lohse (Twente University).]