{"id":{"repo_id":"unm","oai_identifier":"oai:digitalrepository.unm.edu:ne_etds-1023"},"canonical_url":"https://search.dev.ndltd.org/etd/unm/oai:digitalrepository.unm.edu:ne_etds-1023","repository":{"repo_id":"unm","name":"University of New Mexico","base_url":"https://digitalrepository.unm.edu/do/oai/"},"display":{"title":"Nonlinear acceleration methods for even-parity neutron transport","abstract":"Convergence acceleration methods for even-parity transport are being developed that have the potential to speed up transport calculations and provide a natural avenue for an implicitly coupled multiphysics code. An investigation was performed into the acceleration properties of the introduction of a nonlinear quasi-diffusion-like tensor in linear and nonlinear solution schemes. Although poor numerical properties prohibit the direct matrix solution of this reduced system, using it as a preconditioner for the conjugate gradients method proves highly efficient and effective and using it directly in a nonlinear solution scheme proves practical but costly. The results for the linear and nonlinear cases serve as the basis for further research into the application in a full three-dimensional spherical-harmonics even-parity transport code. Once moved into the nonlinear solution scheme, the implicit coupling of the convergence accelerated transport method into codes for other physics can be done seamlessly, providing an efficient, fully implicitly coupled multiphysics code with high order transport.","abstract_html":"Convergence acceleration methods for even-parity transport are being developed that have the potential to speed up transport calculations and provide a natural avenue for an implicitly coupled multiphysics code. An investigation was performed into the acceleration properties of the introduction of a nonlinear quasi-diffusion-like tensor in linear and nonlinear solution schemes. Although poor numerical properties prohibit the direct matrix solution of this reduced system, using it as a preconditioner for the conjugate gradients method proves highly efficient and effective and using it directly in a nonlinear solution scheme proves practical but costly. The results for the linear and nonlinear cases serve as the basis for further research into the application in a full three-dimensional spherical-harmonics even-parity transport code. Once moved into the nonlinear solution scheme, the implicit coupling of the convergence accelerated transport method into codes for other physics can be done seamlessly, providing an efficient, fully implicitly coupled multiphysics code with high order transport.","abstract_has_math":false,"creators":["Martin, William"],"institution":null,"degree_name":"Nuclear Engineering","degree_level":"Thesis","degree_discipline":"Nuclear Engineering","degree_department":null,"school":null,"contributors":["de Oliveira, Cassiano","Prinja, Anil","Coutsias, Evangelos"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2010,"date_issued":"2010-06-25T07:00:00Z","date_published":"2010-06-25T07:00:00Z","updated_at":"2026-07-24T05:26:35Z","subjects":[],"languages":["English"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalrepository.unm.edu/ne_etds/24"],"render_values":[{"text":"https://digitalrepository.unm.edu/ne_etds/24","href":"https://digitalrepository.unm.edu/ne_etds/24","code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/1928/10832","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["de Oliveira, Cassiano","Prinja, Anil","Coutsias, Evangelos"]},{"key":"dc:creator","label":"Author","values":["Martin, William"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Nuclear Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis","Masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Nuclear Engineering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/1928/10832","https://digitalrepository.unm.edu/ne_etds/24"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Convergence acceleration methods for even-parity transport are being developed that have the potential to speed up transport calculations and provide a natural avenue for an implicitly coupled multiphysics code. An investigation was performed into the acceleration properties of the introduction of a nonlinear quasi-diffusion-like tensor in linear and nonlinear solution schemes. Although poor numerical properties prohibit the direct matrix solution of this reduced system, using it as a preconditioner for the conjugate gradients method proves highly efficient and effective and using it directly in a nonlinear solution scheme proves practical but costly. The results for the linear and nonlinear cases serve as the basis for further research into the application in a full three-dimensional spherical-harmonics even-parity transport code. Once moved into the nonlinear solution scheme, the implicit coupling of the convergence accelerated transport method into codes for other physics can be done seamlessly, providing an efficient, fully implicitly coupled multiphysics code with high order transport."]},{"key":"dc:title","label":"Title","values":["Nonlinear acceleration methods for even-parity neutron transport"]}]}],"canonical_facts":{"dc:contributor":["de Oliveira, Cassiano","Prinja, Anil","Coutsias, Evangelos"],"dc:creator":["Martin, William"],"dc:description.abstract":["Convergence acceleration methods for even-parity transport are being developed that have the potential to speed up transport calculations and provide a natural avenue for an implicitly coupled multiphysics code. An investigation was performed into the acceleration properties of the introduction of a nonlinear quasi-diffusion-like tensor in linear and nonlinear solution schemes. Although poor numerical properties prohibit the direct matrix solution of this reduced system, using it as a preconditioner for the conjugate gradients method proves highly efficient and effective and using it directly in a nonlinear solution scheme proves practical but costly. The results for the linear and nonlinear cases serve as the basis for further research into the application in a full three-dimensional spherical-harmonics even-parity transport code. Once moved into the nonlinear solution scheme, the implicit coupling of the convergence accelerated transport method into codes for other physics can be done seamlessly, providing an efficient, fully implicitly coupled multiphysics code with high order transport."],"dc:identifier":["http://hdl.handle.net/1928/10832","https://digitalrepository.unm.edu/ne_etds/24"],"dc:language":["English"],"dc:title":["Nonlinear acceleration methods for even-parity neutron transport"],"thesis:degree_discipline":["Nuclear Engineering"],"thesis:degree_level":["Thesis","Masters"],"thesis:degree_name":["Nuclear Engineering"]},"updated_at":"2026-07-24T05:26:35Z"}