Método espectral determinístico para a solução de problemas de transporte de nêutrons usando a formulação das ordenadas discretas

Abstract

In this thesis dissertation a new numerical approach is presented aiming the development of a method of spectral-nodal class in the deterministic formulation of discrete ordinates(SN), for neutron transport calculations in non-multiplying media with fixed-source. For one-dimensional geometry problems, this methodology is developed for the multigroup energy approximation with arbitrary order of scattering anisotropy L (L ≤ N -1) and prescribed boundary conditions. The Spectral Deterministic Method (SDM), generates numerical solutions that are completely free from spatial truncation errors. For neutron transport problems in X ; Y -geometry, the SDM method is applied to numerically solve the linearly anisotropic (L = 1) transverse-integrated SN nodal equations with constant approximation for the terms corresponding to the transverse leakages terms. This coarse-mesh numerical method in X ; Y -geometry considering monoenergetic problems, is referred to as the SDM-CN method. The simulations results, presented in this work are compared with the traditional fine mesh method Diamond Difference (DD), the spectral Green's function method (SGF), and the Response Matrix (RM) method, in this case, only for one-dimensional, proven the accuracy and stability of the methods MED and MED-CN.