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dc.contributor.authorMarquez Damian, Jose Ignacioen_US
dc.date.accessioned2008-02-07T18:13:47Z
dc.date.available2008-02-07T18:13:47Z
dc.date.issued2007-08-24en_US
dc.identifier.urihttp://hdl.handle.net/1853/19731
dc.description.abstractNuclear reactor design requires the calculation of integral core parameters and power and radiation profiles. These physical parameters are obtained by the solution of the linear neutron transport equation over the geometry of the reactor. In order to represent the fine structure of the nuclear core a very small geometrical mesh size should be used, but the computational capacity available these days is still not enough to solve these transport problems in the time range (hours-days) that would make the method useful as a design tool. This problem is traditionally solved by the solution of simple, smaller problems in specific parts of the core and then use a procedure known as homogenization to create average material properties and solve the full problem with a wider mesh size. The iterative multi-level solution procedure is inspired in this multi-stage approach, solving the problem at fuel-pin (cell) level, fuel assembly and nodal levels. The nested geometrical structure of the finite element representation of a reactor can be used to create a set of restriction/prolongation operators to connect the solution in the different levels. The procedure is to iterate between the levels, solving for the error in the coarse level using as source the restricted residual of the solution in the finer level. This way, the complete problem is only solved in the coarsest level and in the other levels only a pair of restriction/interpolation operations and a relaxation is required. In this work, a multigrid solver is developed for the in-moment equation of the spherical harmonics, finite element formulation of the second order transport equation. This solver is implemented as a subroutine in the code EVENT. Numerical tests are provided as a standalone diffusion solver and as part of a block Jacobi transport solver.en_US
dc.publisherGeorgia Institute of Technologyen_US
dc.subjectMultilevelen_US
dc.subjectMultigriden_US
dc.subjectTransporten_US
dc.subjectReactoren_US
dc.subjectGaussen_US
dc.subjectSeidelen_US
dc.subjectJacobien_US
dc.subjectInterpolationen_US
dc.subjectRestrictionen_US
dc.subjectSpherical harmonicsen_US
dc.subjectFinite elementen_US
dc.subjectFinite elementsen_US
dc.subjectEventen_US
dc.subject.lcshNuclear reactors
dc.subject.lcshMultigrid methods (Numerical analysis)
dc.subject.lcshSpherical harmonics
dc.subject.lcshTransport theory
dc.subject.lcshRadiative transfer
dc.titleMultilevel acceleration of neutron transport calculationsen_US
dc.typeThesisen_US
dc.description.degreeM.S.en_US
dc.contributor.departmentNuclear and Radiological Engineeringen_US
dc.description.advisorCommittee Chair: Stacey, Weston M.; Committee Co-Chair: de Oliveira, Cassiano R.E.; Committee Member: Hertel, Nolan; Committee Member: van Rooijen, Wilfred F.G.en_US


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