Impactful Visualizations
Abstract not provided.
Publications
Physics Geometric Material Model and Experimental Considerations for Exploding Wire Simulation Validation
Abstract not provided.
Providing Relevance to an Engineering-Focused Organization: Detonator Computational Multiphysics
Abstract not provided.
ALEGRA Update: Modernization and Resilience Progress
Abstract not provided.
Contribution to Department of Energy Office of Science DE-FOA-0000508 FY 2011 SBIR/STTR Phase II proposal titled "ALEGRA-MHD Applications to Solid Liner MTF/MIF Confinement Concepts"
Abstract not provided.
The Xygra gun simulation tool
Inductive electromagnetic launchers, or coilguns, use discrete solenoidal coils to accelerate a coaxial conductive armature. To date, Sandia has been using an internally developed code, SLINGSHOT, as a point-mass lumped circuit element simulation tool for modeling coilgun behavior for design and verification purposes. This code has shortcomings in terms of accurately modeling gun performance under stressful electromagnetic propulsion environments. To correct for these limitations, it was decided to attempt to closely couple two Sandia simulation codes, Xyce and ALEGRA, to develop a more rigorous simulation capability for demanding launch applications. This report summarizes the modifications made to each respective code and the path forward to completing interfacing between them.
Simulating coilgun projectile launch using ASC-funded codes
Abstract not provided.
Simulating coilgun projectile launch using ASC codes
Abstract not provided.
Establishing high-fidelity M&S capabilities as a means of experiment prediction and guidance for EM launch applications
Abstract not provided.
Towards a predictive MHD simulation capability for designing hypervelocity magnetically-driven flyer plates and PWclass z-pinch x-ray sources on Z and ZR
Abstract not provided.
Topics on the growth of RT and turbulence with modulated wires and spectroscopic dopants
Abstract not provided.
Seeded perturbations in wire array Z-Pinches
Controlled seeding of perturbations is employed to study the evolution of wire array z-pinch implosion instabilities which strongly impact x-ray production when the 3D plasma stagnates on axis. Wires modulated in radius exhibit locally enhanced magnetic field and imploding bubble formation at discontinuities in wire radius due to the perturbed current path. Wires coated with localized spectroscopic dopants are used to track turbulent material flow. Experiments and MHD modeling offer insight into the behavior of z-pinch instabilities.
Seeded perturbations in wire array z-pinches
Abstract not provided.
Prism : a multi-view visualization toll [i.e. tool] for multi-physics simulations
Abstract not provided.
Prism : a multi-view visualization tool for multi-physics simulation
Complex simulations (in particular, those involving multiple coupled physics) cannot be understood solely using geometry-based visualizations. Such visualizations are necessary in interpreting results and gaining insights into kinematics, however they are insufficient when striving to understand why or how something happened, or when investigating a simulation's dynamic evolution. For multiphysics simulations (e.g. those including solid dynamics with thermal conduction, magnetohydrodynamics, and radiation hydrodynamics) complex interactions between physics and material properties take place within the code which must be investigated in other ways. Drawing on the extensive previous work in view coordination, brushing and linking techniques, and powerful visualization libraries, we have developed Prism, an application targeted for a specific analytic need at Sandia National Laboratories. This multiview scientific visualization tool tightly integrates geometric and phase space views of simulation data and material models. Working closely with analysts, we have developed this production tool to promote understanding of complex, multiphysics simulations. We discuss the current implementation of Prism, along with specific examples of results obtained by using the tool.
ALEGRA-HEDP : version 4.6
ALEGRA is an arbitrary Lagrangian-Eulerian finite element code that emphasizes large distortion and shock propagation in inviscid fluids and solids. This document describes user options for modeling resistive magnetohydrodynamics, thermal conduction, and radiation transport effects, and two material temperature physics.
ALEGRA-MHD : version 4.6
ALEGRA is an arbitrary Lagrangian-Eulerian finite element code that emphasizes large distortion and shock propagation in inviscid fluids and solids. This document describes user options for modeling resistive magnetohydrodynamic, thermal conduction, and radiation emission effects.
ALEGRA : version 4.6
ALEGRA is an arbitrary Lagrangian-Eulerian multi-material finite element code used for modeling solid dynamics problems involving large distortion and shock propagation. This document describes the basic user input language and instructions for using the software.
Seeded perturbations in wire array z-pinches
The impact of 3D structure on wire array z-pinch dynamics is a topic of current interest, and has been studied by the controlled seeding of wire perturbations. First, Al wires were etched at Sandia, creating 20% radial perturbations with variable axial wavelength. Observations of magnetic bubble formation in the etched regions during experiments on the MAGPIE accelerator are discussed and compared to 3D MHD modeling. Second, thin NaF coatings of 1 mm axial extent were deposited on Al wires and fielded on the Zebra accelerator. Little or no axial transport of the NaF spectroscopic dopant was observed in spatially resolved K-shell spectra, which places constraints on particle diffusivity in dense z-pinch plasmas. Finally, technology development for seeding perturbations is discussed.
Study of three-dimensional structure in wire array Z-Pinches by controlled seeding of axial modulations in wire radius
Physical Review Letters
Abstract not provided.
ALEGRA-MHD : Version 4.0
ALEGRA is an arbitrary Lagrangian-Eulerian finite element code that emphasizes large distortion and shock propagation in inviscid fluids and solids. This document describes user options for modeling magnetohydrodynamic, thermal conduction, and radiation emission effects.
Three-dimensional z-pinch wire array modeling with ALEGRA-HEDP
Proposed for publication in the Computer Physics Communications.
An understanding of the dynamics of z-pinch wire array explosion and collapse is of critical interest to the development and future of pulsed power inertial confinement fusion experiments. Experimental results clearly show the extreme three-dimensional nature of the wire explosion and collapse process. The physics of this process can be approximated by the resistive magnetohydrodynamic (MHD) equations augmented by thermal and radiative transport modeling. Z-pinch MHD physics is dominated by material regions whose conductivity properties vary drastically as material passes from solid through melt into plasma regimes. At the same time void regions between the wires are modeled as regions of very low conductivity. This challenging physical situation requires a sophisticated three-dimensional modeling approach matched by sufficient computational resources to make progress in predictive modeling and improved physical understanding.
ALEGRA: User Input and Physics Descriptions Version 4.2
ALEGRA is an arbitrary Lagrangian-Eulerian finite element code that emphasizes large distortion and shock propagation. This document describes the user input language for the code.
23 Results