Aplicação da técnica adjunta em problemas de transporte do tipo fonte-detector na formulação de ordenadas discretas usando um método espectronodal

• Autor(a) principal: Curbelo, Jesús Pérez
• Data de Publicação: 2017
• 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/1/13706
• topic: Adjoint transport problem; Discrete ordinates adjoint equations; Spectral nodal methods; Source-detector problems; Problema adjunto de transporte; Equações adjuntas de ordenadas discretas; Métodos espectronodais; Problemas fonte-detector; Teoria cinética do transporte Método das ordenadas discretas; Teoria do transporte de nêutron Métodos de simulação; Teoria do transporte de nêutron Modelos matemáticos; Partículas (Física nuclear) Transporte Métodos de simulação; CNPQ::ENGENHARIAS::ENGENHARIA NUCLEAR

The application of the adjoint technique for solving source-detector discrete ordinates (SN) transport problems by using a spectral nodal method is presented in this thesis work. For slab-geometry adjoint SN problems, the adjoint spectral Green's function method (Adjoint-SGF) is extended to multigroup problems considering arbitrary L'th-order of scattering anisotropy, provided L < N, and non-zero prescribed boundary conditions for the forward SN transport problem. The adjoint spectral Green's function (Adjoint-SGF) method converges numerical solutions that are completely free from spatial truncation errors. For one-speed X; Y -geometry discrete ordinates (SN) adjoint transport problems considering linearly anisotropic scattering in non-multiplying media, the Adjoint-SGF method is applied to solve the adjoint "one-dimensional" transverse-integrated SN nodal equations with constant approximation for the terms corresponding to the transverse leakages in the forward problem. This coarse-mesh method is referred to as the Adjoint-SGF-CN method. In both one-dimensional and two-dimensional cases, it is used the partial one-node block inversion (NBI) scheme for iteratively solving the Adjoint-SGF equations. Partial adjoint NBI scheme uses the most recent estimates for the node-edge adjoint angular fluxes outgoing a given discretization node, to solve the resulting adjoint SN problem in that node for all the incoming adjoint angular fluxes, which constitute the outgoing adjoint angular fluxes for the adjacent node in the sweeping direction. Numerical results are given to illustrate the present spectral nodal methods' features and some advantages of using the adjoint technique in source-detector problems.