Experimental investigation of a twice-shocked spherical gas inhomogeneity with particle image velocimetry

• Published in: Shock waves Vol. 21; no. 3; pp. 225 - 231
• Main Authors: Haehn, N., Weber, C., Oakley, J., Anderson, M., Ranjan, D., Bonazza, R.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2011; Springer Nature B.V
• Subjects: Acoustics; Argon; Atomizing; Condensed Matter Physics; Engineering; Engineering Fluid Dynamics; Engineering Thermodynamics; Fluid- and Aerodynamics; Heat and Mass Transfer; Inhomogeneity; Mie scattering; Original Article; Particle image velocimetry; Shock waves; Soap films; Thermodynamics; Tube ends; Velocity distribution; Vortex rings; Vorticity; Mie; Bubble; Reshock; PIV; Vorticity; Compressible
• ISSN: 0938-1287; 1432-2153
• DOI: 10.1007/s00193-011-0299-x

Results are presented from an experimental investigation into the interaction of a planar shock wave with a vortex ring. A free-falling spherical soap bubble is traversed by the incident shock wave and develops into a vortex ring as a result of baroclinically deposited vorticity ( ). The vortex ring translates with a velocity relative to the particle velocity behind the shock wave due to circulation. After the shock wave reflects from the tube end wall, it traverses the vortex ring (this process is called “reshock”) and deposits additional vorticity. Planar Mie scattering is used to visualize the atomized soap film at high frame rates (up to 10,000 fps). Particle image velocimetry (PIV) was performed for an argon bubble in nitrogen accelerated by a M = 1.35 shock wave. Circulation was determined from the PIV velocity field and found to agree well with Kelvin’s vortex ring model.