title: Experimental investigation of primary and secondary features in high-mach-number shock-bubble interaction.
abstract: Experiments to study the compression and unstable evolution of an isolated soap-film bubble containing helium, subjected to a strong planar shock wave (M=2.95) in ambient nitrogen, have been performed in a vertical shock tube of square internal cross section using planar laser diagnostics. The early phase of the interaction process is dominated by the formation of a primary vortex ring due to the baroclinic source of vorticity deposited during the shock-bubble interaction, and the mass transfer from the body of the bubble to the vortex ring. The late time (long after shock interaction) study reveals the presence of a secondary baroclinic source of vorticity at high Mach number which is responsible for the formation of counterrotating secondary and tertiary vortex rings and the subsequent larger rate of elongation of the bubble.
authors.affiliation: Engineering Physics Department, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706, USA.
authors.forename: Devesh
authors.initials: D
authors.lastname: Ranjan
authors.forename: John
authors.initials: J
authors.lastname: Niederhaus
authors.forename: Bradley
authors.initials: B
authors.lastname: Motl
authors.forename: Mark
authors.initials: M
authors.lastname: Anderson
authors.forename: Jason
authors.initials: J
authors.lastname: Oakley
authors.forename: Riccardo
authors.initials: R
authors.lastname: Bonazza