Simulations of material mixing in laser-driven reshock experiments

Journal Article · Fri Feb 15 04:00:00 EST 2013 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4793443· OSTI ID:22113441

Haines, Brian M.; Grinstein, Fernando F.; Welser-Sherrill, Leslie; Fincke, James R. ^[1]

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1. Los Alamos National Laboratory, MS F644, Los Alamos, New Mexico 87545 (United States)

We perform simulations of a laser-driven reshock experiment [Welser-Sherrill et al., High Energy Density Phys. (unpublished)] in the strong-shock high energy-density regime to better understand material mixing driven by the Richtmyer-Meshkov instability. Validation of the simulations is based on direct comparison of simulation and radiographic data. Simulations are also compared with published direct numerical simulation and the theory of homogeneous isotropic turbulence. Despite the fact that the flow is neither homogeneous, isotropic nor fully turbulent, there are local regions in which the flow demonstrates characteristics of homogeneous isotropic turbulence. We identify and isolate these regions by the presence of high levels of turbulent kinetic energy (TKE) and vorticity. After reshock, our analysis shows characteristics consistent with those of incompressible isotropic turbulence. Self-similarity and effective Reynolds number assessments suggest that the results are reasonably converged at the finest resolution. Our results show that in shock-driven transitional flows, turbulent features such as self-similarity and isotropy only fully develop once de-correlation, characteristic vorticity distributions, and integrated TKE, have decayed significantly. Finally, we use three-dimensional simulation results to test the performance of two-dimensional Reynolds-averaged Navier-Stokes simulations. In this context, we also test a presumed probability density function turbulent mixing model extensively used in combustion applications.

• OSTI ID: 22113441
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 2 Vol. 20; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CHARGES
COMPARATIVE EVALUATIONS
COMPUTERIZED SIMULATION
CORRELATIONS
DISTRIBUTION
ENERGY DENSITY
ISOTROPY
KINETIC ENERGY
LIGHT TRANSMISSION
MIXING
NAVIER-STOKES EQUATIONS
PLASMA
PLASMA DIAGNOSTICS
PLASMA INSTABILITY
PLASMA SIMULATION
PROBABILITY DENSITY FUNCTIONS
REYNOLDS NUMBER
SHOCK WAVES
TURBULENCE