News from bubble dynamics: High static pressures, shock waves and interior dynamics

Abstract

Three topics from the vast area of bubble dynamics are addressed: (i) the influence of high static pressure on the oscillation of a spherical bubble in a sound field (calculations), (ii) the response of a bubble to a shock wave (experiments), and (iii) the interior dynamics as seen by molecular dynamics calculations. The notion of a bubble habitat is used for positionally and spherically stable, not dissolving bubbles in some two-dimensional space of parameters (mainly bubble radius at rest and sound pressure amplitude) for presenting the results. An elevated static pressure substantially enlarges the bubble habitat and thus the range, where bubbles can be stably trapped. Shock wave - bubble interaction is investigated in the context of laser induced bubbles collapsing in the neighborhood of a solid, plane boundary. Jet development as influenced by both the boundary and by a shock wave propagating parallel to the boundary is studied by high speed photography. The interior of a bubble is explored by molecular dynamics calculations. Temperature and density are calculated for different species in the bubble, as there are noble gases, water vapor and its decomposition products.