A high energy density shock driven Kelvin-Helmholtz shear layer experiment

Journal Article · Fri May 15 04:00:00 EDT 2009 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3096790· OSTI ID:21277176

Hurricane, O A; Hansen, J F; Robey, H F; Remington, B A; Bono, M J ^[1]; Harding, E C; Drake, R P; Kuranz, C C ^[2]

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1. Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States)
2. Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, 2455 Hayward St., Ann Arbor, Michigan 48109-2143 (United States)

Radiographic data from a novel and highly successful high energy density Kelvin-Helmholtz (KH) instability experiment is presented along with synapses of the theory and simulation behind the target design. Data on instability growth are compared to predictions from simulation and theory. The key role played by baroclinic vorticity production in the functioning of the target and the key design parameters are also discussed. The data show the complete evolution of large distinct KH eddies, from formation to turbulent break-up. Unexpectedly, low density bubbles comparable to the vortex size are observed forming in the free-stream region above each vortex at late time. These bubbles have the appearance of localized shocks, possibly supporting a theoretical fluid dynamics conjecture about the existence of supersonic bubbles over the vortical structure [transonic convective Mach numbers, D. Papamoschou and A. Roshko, J. Fluid Mech. 197, 453 (1988)] that support localized shocks (shocklets) not extending into the free stream (P. E. Dimotakis, Proceedings of the 22nd Fluid Dynamics, Plasma Dynamics and Lasers Conference, 1991, Paper No. AIAA 91-1724). However, it is also possible that these low density bubbles are the result of a cavitationlike effect. Hypothesis that may explain the appearance of low density bubbles will be discussed.

• OSTI ID: 21277176
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 5 Vol. 16; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ENERGY DENSITY
FLUID MECHANICS
HELMHOLTZ INSTABILITY
INSTABILITY GROWTH RATES
PLASMA
SHOCK WAVES
SUPERSONIC FLOW
VORTICES