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1	Aplicação do método da expansão em funções hierárquicas na solução das equações de navier-Stokes em duas dimensões para fluidos compressíveis em alta velocidade CONTI, THADEU das N. 09 October 2014 (has links) Made available in DSpace on 2014-10-09T12:53:37Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:08:27Z (GMT). No. of bitstreams: 1 12226.pdf: 2981863 bytes, checksum: f04d559e0b2d5d5ba05718e2738e9989 (MD5) / Tese (Doutoramento) / IPEN/T / Escola Politécnica, Universidade de Sao Paulo - POLI/USP FLUID FLOW COMPERSIBLE FLOW NODAL EXPANSION METHOD NAVIER-STOKES EQUATIONS
2	Aplicação do método da expansão em funções hierárquicas na solução das equações de navier-Stokes em duas dimensões para fluidos compressíveis em alta velocidade CONTI, THADEU das N. 09 October 2014 (has links) Made available in DSpace on 2014-10-09T12:53:37Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:08:27Z (GMT). No. of bitstreams: 1 12226.pdf: 2981863 bytes, checksum: f04d559e0b2d5d5ba05718e2738e9989 (MD5) / Tese (Doutoramento) / IPEN/T / Escola Politécnica, Universidade de Sao Paulo - POLI/USP fluid flow compressible flow nodal expansion method navier-stokes equations
3	Solution of algebraic problems arising in nuclear reactor core simulations using Jacobi-Davidson and Multigrid methods Havet, Maxime M 10 October 2008 (has links) The solution of large and sparse eigenvalue problems arising from the discretization of the diffusion equation is considered. The multigroup diffusion equation is discretized by means of the Nodal expansion Method (NEM) [9, 10]. A new formulation of the higher order NEM variants revealing the true nature of the problem, that is, a generalized eigenvalue problem, is proposed. These generalized eigenvalue problems are solved using the Jacobi-Davidson (JD) method [26]. The most expensive part of the method consists of solving a linear system referred to as correction equation. It is solved using Krylov subspace methods in combination with aggregation-based Algebraic Multigrid (AMG) techniques. In that context, a particular aggregation technique used in combination with classical smoothers, referred to as oblique geometric coarsening, has been derived. Its particularity is that it aggregates unknowns that are not coupled, which has never been done to our knowledge. A modular code, combining JD with an AMG preconditioner, has been developed. The code comes with many options, that have been tested. In particular, the instability of the Rayleigh-Ritz [33] acceleration procedure in the non-symmetric case has been underlined. Our code has also been compared to an industrial code extracted from ARTEMIS. preconditioning eigenvalue problem Krylov Nodal Expansion Method Aggregation Algebraic Multigrid Jacobi-Davidson
4	Analise termo hidrodinamica de uma centrifuga a contracorrente ANDRADE, DELVONEI A. de 09 October 2014 (has links) Made available in DSpace on 2014-10-09T12:43:20Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:10Z (GMT). No. of bitstreams: 1 06481.pdf: 5013180 bytes, checksum: 7fd69f45c605162fe74bdcf0decbd24d (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP gas centrifuges counter current rotors thermal analysis gas flow hydrodynamic model nodal expansion method isotope separation
5	Analise termo hidrodinamica de uma centrifuga a contracorrente ANDRADE, DELVONEI A. de 09 October 2014 (has links) Made available in DSpace on 2014-10-09T12:43:20Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:10Z (GMT). No. of bitstreams: 1 06481.pdf: 5013180 bytes, checksum: 7fd69f45c605162fe74bdcf0decbd24d (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP gas centrifuges counter current rotors thermal analysis gas flow hydrodynamic model nodal expansion method isotope separation
6	Solution of algebraic problems arising in nuclear reactor core simulations using Jacobi-Davidson and multigrid methods Havet, Maxime 10 October 2008 (has links) The solution of large and sparse eigenvalue problems arising from the discretization of the diffusion equation is considered. The multigroup<p>diffusion equation is discretized by means of the Nodal expansion Method (NEM) [9, 10]. A new formulation of the higher order NEM variants revealing the true nature of the problem, that is, a generalized eigenvalue problem, is proposed. These generalized eigenvalue problems are solved using the Jacobi-Davidson (JD) method<p>[26]. The most expensive part of the method consists of solving a linear system referred to as correction equation. It is solved using Krylov subspace methods in combination with aggregation-based Algebraic Multigrid (AMG) techniques. In that context, a particular<p>aggregation technique used in combination with classical smoothers, referred to as oblique geometric coarsening, has been derived. Its particularity is that it aggregates unknowns that<p>are not coupled, which has never been done to our<p>knowledge. A modular code, combining JD with an AMG preconditioner, has been developed. The code comes with many options, that have been tested. In particular, the instability of the Rayleigh-Ritz [33] acceleration procedure in the non-symmetric case has been underlined. Our code has also been compared to an industrial code extracted from ARTEMIS. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished Sciences de l'ingénieur Physique Nuclear energy Nuclear reactors -- Simulation methods Neutron flux Neutrons -- Scattering Energie nucléaire Flux de neutrons Neutrons -- Diffusion Algebraic Multigrid Aggregation Nodal Expansion Method Krylov eigenvalue problem preconditioning Jacobi-Davidson

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