Experimental study of the richtmyer-meshkov instability, including amplitude and wavelength variations

Conference · Tue Jul 01 04:00:00 EDT 1997

OSTI ID:641037

Miller, P L; Logory, L M; Peyser, T A; Farley, D R; Murray, s D; Burke, E W; Stry, P E

We report on results of an experimental study of the Richtmyer- Meshkov instability. The growth of the mixing region in the nonlinear regime is measured for a set of cases in which the amplitude and wavelength of the initial perturbation are varied systematically. The experiments are conducted on the Nova laser facility, and use a Nova hohlraum as a driver source to launch a high-Mach-number shock into a miniature shock tube attached to the hohlraum. The shock tube contains brominated plastic and low-density carbon foam as the two working fluids, with a micro-machined, triangular sawtooth interface between them serving as the initial perturbation. The sawtooth perturbation waveform is dominated by a single mode, and the perturbation amplitudes are chosen to expedite transition into the nonlinear phase of the instability. The shock, upon crossing the perturbation at the interface, instigates the Richtmyer- Meshkov instability. The resulting growth of the mixing region is diagnosed radiographically. Quantitative measurements of the temporal growth of the width of the mixing region are made for six different combinations of amplitude and wavelength, building upon previous results which employed a single amplitude/wavelength combination. Data from both experiment and supporting simulations suggest that the nonlinear growth of the mix width admits a logarithmic time dependence. The results also suggest that, properly normalized, the total mixing width grows in a nearly self-similar fashion, with a weak shape dependence.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 641037
• Report Number(s): UCRL-JC--127797; CONF-970764--; ON: DE98050857; CNN: W-7405-Eng-48
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
MIXING
PLASMA INSTABILITY
US NATIONAL IGNITION FACILITY
WAVELENGTHS