Métodos espectronodais para cálculos de transporte de partículas neutras com fonte fixa na formulação de ordenadas discretas e multigrupo de energia

• Autor(a) principal: Menezes, Welton Alves de
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/13651
• topic: Discrete ordinates; Multigroup model; Spectral nodal method; Fixedsource problems; Neutral particle transport; Formulação de ordenadas discretas; Modelo multigrupo; Método espectronodal; Problemas de fonte fixa; Transporte de partículas neutras; CNPQ::ENGENHARIAS::ENGENHARIA NUCLEAR

A spectral nodal method is described for neutral particle energy multigroup fixed-source transport problems in cartesian geometry in the discrete ordinates (SN) formulation. For slab geometry the offered multigroup spectral nodal method is referred to as the spectral Green s function (SGF) method with the one-node block inversion (NBI) iterative scheme, which converges numerical solutions to multigroup slab-geometry SN problems, that are completely free from spatial truncation errors for scattering anisotropy of order L, provided L < N. For X; Y-geometry, the offered multigroup spectral nodal method is based on transverse integrations of the SN equations inside the discretization nodes, separately in x- and y- coordinate directions. Since the transverse-leakage terms are approximated by constants, the resulting nodal method is referred to as the multigroup SGF-contant nodal (SGF-CN) method, which is applied for multigroup X; Y-geometry fixed-source SN problems with isotropic scattering. Numerical results are presented to illustrate the efficiency of the SGF and SGF-CN codes and the accuracy of the converged numerical solutions in coarse-mesh calculations.