A Comparison of Radiation Transport Methods in Axisymmetric Geometries.

Abstract

The radiative transfer equation with a fixed source and fixed absorption is studied in axisymmetric geometries. A comparison of solutions for several model problems is presented using two different numerical schemes. The first scheme uses the radiation diffusion approximation with flux-limiting; the second, a multi-directional ray trace. The underlying spatial grid over which the solutions are calculated is a distorted set of quadrilaterals for application to two dimensional, Lagrangian, radiation-hydrodynamic codes. The results of the numerical solutions indicate that both schemes are accurate in radiating, optically thick regions. In source-free, purely absorbing regions, the accuracy decreases, but much more so for the diffusion approach than the ray tracing one. The major advantages of the latter approach over the former are; (i) the accuracy can be easily improved by increasing the number of rays for example, and (ii) computation time can be shorter for multi frequency calculations with more than about 10 frequencies.

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Document Details

Document Type
Technical Report
Publication Date
Oct 06, 1986
Accession Number
ADA173966

Entities

People

  • John L. Giuliani Jr.

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Absorption Coefficients
  • Classification
  • Computations
  • Differential Equations
  • Equations
  • Geometry
  • Hydrocodes
  • Laser Targets
  • Radiation
  • Radiative Transfer
  • Ray Tracing
  • Scattering
  • Security
  • Steady State
  • Test And Evaluation
  • Two Dimensional
  • X Rays

Fields of Study

  • Physics

Readers

  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Plasma Physics / Magnetohydrodynamics
  • Wave Propagation and Nonlinear Chaotic Dynamics.