A Finite Element Projection Method for the Solution of Particle Transport Problems with Anisotropic Scattering.

Abstract

A solution method for solving particle transport problems has been developed. This solution approach embodies a finite element projection technique and a related equivalent variational Raleigh-Ritz formalism. Particle flux in the transport equation is expressed as a linear and separable sum of odd and even components in the direction variables. Then a classical variational principle is obtained and shown to be equivalent to a Bubnov-Galerkin projected solution. A dual finite element basis of polynomial splines in space and spherical harmonics in angle is used in the Bubnov-Galerkin equations. The general theoretical and numerical problem formalism is carried out in a 3-dimensional geometry with anisotropic scattering and with a piecewise constant energy dependence. This is a seven-dimensional problem with time dependence, three spatial and two angular or directional variables and with a multigroup treatment of the energy dependence. The boundary conditions for most physical problems of interest are dealt with explicitly and rigorously by a classical minimization (variational) principle. The computational validation of the method was obtained by a computer solution to the air-over-ground problem. This problem is of significant interest in the areas of nuclear weapons effects and radiation physics.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1984
Accession Number
ADA145382

Entities

People

  • E. E. Wills

Organizations

  • Air Force Institute of Technology

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Air Force
  • Boltzmann Equation
  • Boundary Value Problems
  • Calculus Of Variations
  • Computational Fluid Dynamics
  • Computational Science
  • Computer Programs
  • Differential Equations
  • Finite Element Analysis
  • Geometry
  • Mathematical Models
  • Nuclear Energy
  • Numerical Analysis
  • Partial Differential Equations
  • Three Dimensional
  • Two Dimensional
  • Variational Principles

Fields of Study

  • Mathematics
  • Physics

Readers

  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Plasma Physics / Magnetohydrodynamics

Technology Areas

  • Space