Simulation ensemble for a laser–driven shear experiment

Journal Article · Sun Sep 15 04:00:00 EDT 2013 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4820768· OSTI ID:22220592

Haines, Brian M.; Grinstein, Fernando F.; Welser–Sherrill, Leslie; Fincke, James R.; Doss, Forrest W. ^[1]

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1. Los Alamos National Laboratory, MS T087, Los Alamos, New Mexico 87545 (United States)

We perform an ensemble of simulations of a laser-driven shear experiment [L. Welser-Sherrill et al., “Two laser-driven mix experiments to study reshock and shear,” High Energy Density Phys. J. 9(3), 496–499 (2013)] in the strong-shock high energy-density regime to better understand material mixing driven by the Kelvin–Helmholtz instability. Each simulation uses a different realization of random initial interface perturbations based on data from targets used in experiments. 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. Our analysis shows characteristics consistent with those of incompressible isotropic turbulence. Our results show that turbulent features are present both near the shock front and in a separated region in the wake of the shock. These features develop and decay at different rates. Finally, we use the ensemble of three-dimensional simulations 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: 22220592
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 9 Vol. 20; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COMPUTERIZED SIMULATION
ENERGY DENSITY
HELMHOLTZ INSTABILITY
LASERS
MIXING
NAVIER-STOKES EQUATIONS
PERTURBATION THEORY
PROBABILITY DENSITY FUNCTIONS
REYNOLDS NUMBER
SHEAR
SHOCK WAVES
TURBULENCE