title: The role of gas in ultrasonically driven vapor bubble growth.
abstract: In this paper we study both experimentally and theoretically the dynamics of an ultrasound-driven vapor bubble of perfluoropentane (PFP) inside a droplet of the same liquid, immersed in a water medium superheated with respect to the PFP boiling point. We determine the temporal evolution of the bubble radius with ultra-high speed imaging at 20 million frames per second. In addition, we model the vapor-gas bubble dynamics, based on a Rayleigh-Plesset-type equation, including thermal and gas diffusion inside the liquid. We compare the numerical results with the experimental data and find good agreement. We underline the fundamental role of gas diffusion in order to prevent total recondensation of the bubble at collapse.
authors.affiliation: Physics of Fluids Group, MIRA Institute of Biomedical Technology and Technical Medicine, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands. o.shpak@utwente.nl
authors.forename: Oleksandr
authors.initials: O
authors.lastname: Shpak
authors.forename: Laura
authors.initials: L
authors.lastname: Stricker
authors.forename: Michel
authors.initials: M
authors.lastname: Versluis
authors.forename: Detlef
authors.initials: D
authors.lastname: Lohse
mesh_terms: D004058:Diffusion; D005466:Fluorocarbons / Q000737:chemistry; D005740:Gases; D057446:Hydrodynamics; D061848:Optical Imaging; D013010:Sonication; D013997:Time Factors; D014835:Volatilization; D010420:Pentanes
chemical_list: D005466:Fluorocarbons; D005740:Gases; C008806:perfluoropentane; D010420:Pentanes