Modeling Fluid Instabilities in Inertial Confinement Fusion Hydrodynamics Codes

Abstract

The numerical tools typically used to model the evolution of fluid instabilities in inertial confinement fusion (ICF) hydrodynamics codes are examined, and some are found to have properties which would seem to be incompatible with the accurate modeling of small-amplitude perturbations, i.e., perturbations in the linear stage of evolution. In particular a "differentiability condition" which is satisfied by the physics in such situations is not necessarily satisfied by the numerical algorithms in typical use. It is demonstrated that it is possible to remove much of the non-differentiability in many cases, and that substantial improvement in one's ability to accurately model the evolution of small amplitude perturbations can result. First a simple example involving a non-differentiable radiation transport algorithm is shown, and then the non- differentiabilities introduced by the use of upwind and "high resolution" hydrodynamics algorithms are analyzed.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2005
Accession Number
ADA483118

Entities

People

  • A. L. Velikovich
  • Andrew J. Schmitt
  • John H. Gardner
  • Steven T. Zalesak

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Amplitude
  • Computational Fluid Dynamics
  • Computational Science
  • Coordinate Systems
  • Equations
  • Fluid Dynamics
  • Geometry
  • Grids
  • High Resolution
  • Hydrodynamics
  • Instability
  • Materials
  • Numerical Analysis
  • Physics
  • Thermal Conductivity
  • Time Intervals
  • Two Dimensional

Readers

  • Computational Fluid Dynamics (CFD)
  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Pulsed Power and Plasma Physics.