Results 231 to 240 of about 42,606 (261)
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Journal of Computational and Theoretical Transport, 2018
Presented here is the application of an adjoint technique for solving source-detector discrete ordinates (SN) transport problems by using a spectral nodal method.
Jesús P. Curbelo +2 more
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Presented here is the application of an adjoint technique for solving source-detector discrete ordinates (SN) transport problems by using a spectral nodal method.
Jesús P. Curbelo +2 more
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Progress in Nuclear Energy, 2010
Computer modeling of radiation deep penetration problems is historically based on the discrete ordinates (SN) formulation. For efficiency reasons, besides accuracy, coarse-mesh spatial discretization is desirable. The spectral Green’s function (SGF) methods form a class of accurate coarse-mesh numerical methods as they use polynomial approximations ...
Dany S. Dominguez +3 more
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Computer modeling of radiation deep penetration problems is historically based on the discrete ordinates (SN) formulation. For efficiency reasons, besides accuracy, coarse-mesh spatial discretization is desirable. The spectral Green’s function (SGF) methods form a class of accurate coarse-mesh numerical methods as they use polynomial approximations ...
Dany S. Dominguez +3 more
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Physica Scripta, 2021
Abstract This paper deals with the multi-dimensional coupled viscous Burgers’ equations, using the method of lines (MOL). Indeed, the solutions are approximated by their Lagrange interpolation on a set of Jacobi-type nodes. Then, an appropriate differentiation matrix is used to approximate the first and the second partial derivatives ...
Bashar Zogheib +3 more
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Abstract This paper deals with the multi-dimensional coupled viscous Burgers’ equations, using the method of lines (MOL). Indeed, the solutions are approximated by their Lagrange interpolation on a set of Jacobi-type nodes. Then, an appropriate differentiation matrix is used to approximate the first and the second partial derivatives ...
Bashar Zogheib +3 more
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A nodal spectral stiffness matrix for the finite-element method
IMA Journal of Applied Mathematics, 2008In this paper, shape functions are proposed for the spectral finite-element method aiming to finding a nodal spectral stiffness matrix. The proposed shape functions obtain a nearly diagonal ĞD stiffness matrix with better conditioning than using the Lagrange and Jacobi bases.
M. L. Bittencourt, T. G. Vazquez
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Progress in spectral nodal methods applied to discrete ordinates transport problems
Progress in Nuclear Energy, 1998Abstract We describe the recent advances in spectral nodal methods applied to discrete ordinates ( S N ) transport problems. The basic numerical schemes that we present are the spectral Green's function (SGF) nodal method and the simplified S N method.
Ricardo C. Barros +4 more
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Shock Capturing For High-Order Nodal Spectral Element Methods
2021The presence of discontinuities in nonlinear hyperbolic conservation laws is a long-standing challenge in the development of high-order numerical methods. In this talk, I will present an approach to shock capturing for discontinuous spectral element methods which uses invariant domain preservation techniques to construct a low-order scheme devoid of ...
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Nuclear Science and Engineering, 1996
The spectral history problem encountered in reconstructing local homogeneous power distributions is investigated. Because of difficulties in most nodal codes concerning spectral interactions between neighboring assemblies when rebuilding the local power distribution, nodal codes assume a constant spectrum or do not properly consider local spectrum ...
C. H. Lee +3 more
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The spectral history problem encountered in reconstructing local homogeneous power distributions is investigated. Because of difficulties in most nodal codes concerning spectral interactions between neighboring assemblies when rebuilding the local power distribution, nodal codes assume a constant spectrum or do not properly consider local spectrum ...
C. H. Lee +3 more
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A spectral nodal method for one-group X,Y,Z-cartesian geometry discrete ordinates problems
Annals of Nuclear Energy, 1996Abstract The solution of one-group discrete ordinates S N problems with linearly anisotropic scattering in x , y , z - cartesian geometry has been studied by using SGF-CN “spectral Green's function-constant nodal’ method, developed first by De Barros and Larsen (1990–1992) for one dimensional and two dimensional x , y - cartesian ...
Anli F., Güngör S.
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Transport Theory and Statistical Physics, 2004
Abstract In this paper we present the recent advances in spectral nodal methods for numerically solving neutron-diffusion eigenvalue problems in Cartesian geometry. For one‐dimensional two‐energy group diffusion criticality problems, we describe the use of nonconventional albedo boundary conditions that substitute approximately the reflective ...
Ricardo C. Barros +4 more
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Abstract In this paper we present the recent advances in spectral nodal methods for numerically solving neutron-diffusion eigenvalue problems in Cartesian geometry. For one‐dimensional two‐energy group diffusion criticality problems, we describe the use of nonconventional albedo boundary conditions that substitute approximately the reflective ...
Ricardo C. Barros +4 more
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Applied Numerical Analysis & Computational Mathematics, 2005
From the authors' abstract: We propose and analyze an orthogonal non-polynomial nodal basis on triangles for discontinuous spectral element methods (DSEMs) for solving Maxwell's equations. It is based on the standard tensor product of the Lagrange interpolation polynomials and a ``collapsing'' mapping between the standard square and the standard ...
Deng, Shaozhong, Cai, Wei
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From the authors' abstract: We propose and analyze an orthogonal non-polynomial nodal basis on triangles for discontinuous spectral element methods (DSEMs) for solving Maxwell's equations. It is based on the standard tensor product of the Lagrange interpolation polynomials and a ``collapsing'' mapping between the standard square and the standard ...
Deng, Shaozhong, Cai, Wei
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