AN EXTENSION OF EDDINGTON APPROXIMATION

被引:52
作者
POMRANING, GC
机构
[1] University of California, Los Alamos Scientific Laboratory, Los Alamos, NM
关键词
D O I
10.1016/0022-4073(69)90036-3
中图分类号
O43 [光学];
学科分类号
070207 ; 0803 ;
摘要
A modification of the Eddington approximation to the equation of radiative transfer is suggested. The basic element of this approach is the derivation of an approximate angular distribution for the specific intensity appropriate to the problem under consideration, rather than an assumption of near isotropy as in the Eddington approximation. The resulting equations retain the simplicity of the Eddington formulation and consist of two coupled first order differential equations for the energy density and radiative flux. Boundary conditions for these equations are derived using arguments from the calculus of variations. The modified formulation reduces to the standard Eddington approximation in those cases for which the latter is an accurate description of radiative transfer. In other instances, the two approximations, while qualitatively similar, give quantitatively different results. Numerical examples indicate that the modified formulation suggested here is substantially more accurate than the standard Eddington approximation. The formulation is given in full geometric generality, but is restricted to grey, steady-state radiative transfer. The basic idea of this approach, however, should also be applicable to time-dependent, multifrequency problems. © 1969.
引用
收藏
页码:407 / +
页数:1
相关论文
共 27 条
  • [1] CARLSON BG, 1958, 2 P INT C PEAC US, V16, P535
  • [2] CASE KM, 1953, INTRODUCTION THEORY, P49
  • [3] CASE KM, 1953, INTRODUCTION THEORY, P129
  • [4] CASE KM, 1953, INTRODUCTION THEORY, P21
  • [5] CASE KM, 1953, INTRODUCTION THEORY, P28
  • [6] Chandrasekhar S., 1960, RAD TRANSFER, P1
  • [7] Chandrasekhar S, 1960, RAD TRANSFER, P54
  • [8] DAVISON B, 1957, NEUTRON TRANSPORT TH, P126
  • [9] DAVISON B, 1957, NEUTRON TRANSPORT TH, P87
  • [10] DAVISON B, 1957, NEUTRON TRANSPORT TH, P116