{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/99436"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/99436","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Maximum entropy quadratic model to characterize chemical non-equilibrium in re-entry flows","abstract":"This thesis presents the study of an advanced non-equilibrium model for state-specific chemical kinetics based on method of moments. The focus of this project is on the rovibrational chemical kinetics of the N2-N system. Internal excitation, dissociation, recombination and energy transfer reactions, which are important processes in aerothermodynamics, are studied. The kinetic and thermodynamic data is obtained from ab-initio calculations performed at NASA Ames Research Center. Previous analysis of the population distribution revealed that the population of the low lying energy levels of nitrogen molecules strongly deviates from a Boltzmann distribution, and the non-equilibrium distribution exhibits significant curvature. By invoking the maximum entropy principle subject to a series of constraints, the logarithm of distribution function is reconstructed using quadratic functions in the internal energy space of the molecular species. The results of the numerical simulations for an ideal chemical reactor show that the quadratic model captures the excitation and dissociation profiles accurately by using only three to seven groups thereby reducing the computational costs for non-equilibrium flow simulations significantly.","abstract_html":"This thesis presents the study of an advanced non-equilibrium model for state-specific chemical kinetics based on method of moments. The focus of this project is on the rovibrational chemical kinetics of the N2-N system. Internal excitation, dissociation, recombination and energy transfer reactions, which are important processes in aerothermodynamics, are studied. The kinetic and thermodynamic data is obtained from ab-initio calculations performed at NASA Ames Research Center. Previous analysis of the population distribution revealed that the population of the low lying energy levels of nitrogen molecules strongly deviates from a Boltzmann distribution, and the non-equilibrium distribution exhibits significant curvature. By invoking the maximum entropy principle subject to a series of constraints, the logarithm of distribution function is reconstructed using quadratic functions in the internal energy space of the molecular species. The results of the numerical simulations for an ideal chemical reactor show that the quadratic model captures the excitation and dissociation profiles accurately by using only three to seven groups thereby reducing the computational costs for non-equilibrium flow simulations significantly.","abstract_has_math":false,"creators":["Sharma Priyadarshini, Maitreyee"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Aerospace Engineering","degree_department":null,"school":null,"contributors":["Panesi, Marco"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2018,"date_issued":"2018-03-13T15:49:21Z","date_published":"2018-03-13T15:49:21Z","updated_at":"2026-07-22T22:24:37Z","subjects":["Non-equilibrium flows","Reduced order modeling","Method of moments"],"languages":["en"],"rights":["Copyright 2017 Maitreyee Sharma Priyadarshini"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/99436","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Panesi, Marco"]},{"key":"dc:creator","label":"Author","values":["Sharma Priyadarshini, Maitreyee"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2018-03-13T15:49:21Z","2017-12-15","2017-12"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Aerospace Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Non-equilibrium flows","Reduced order modeling","Method of moments"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2017 Maitreyee Sharma Priyadarshini"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/99436"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This thesis presents the study of an advanced non-equilibrium model for state-specific chemical kinetics based on method of moments. The focus of this project is on the rovibrational chemical kinetics of the N2-N system. Internal excitation, dissociation, recombination and energy transfer reactions, which are important processes in aerothermodynamics, are studied. The kinetic and thermodynamic data is obtained from ab-initio calculations performed at NASA Ames Research Center. Previous analysis of the population distribution revealed that the population of the low lying energy levels of nitrogen molecules strongly deviates from a Boltzmann distribution, and the non-equilibrium distribution exhibits significant curvature. By invoking the maximum entropy principle subject to a series of constraints, the logarithm of distribution function is reconstructed using quadratic functions in the internal energy space of the molecular species. The results of the numerical simulations for an ideal chemical reactor show that the quadratic model captures the excitation and dissociation profiles accurately by using only three to seven groups thereby reducing the computational costs for non-equilibrium flow simulations significantly.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2018-03-13 without embargo terms","The student, Maitreyee Sharma Priyadarshini, accepted the attached license on 2017-12-14 at 14:02.","The student, Maitreyee Sharma Priyadarshini, submitted this Thesis for approval on 2017-12-15 at 09:28.","This Thesis was approved for publication on 2017-12-15 at 11:18.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11982 on 2018-03-13 at 10:12:50","Made available in DSpace on 2018-03-13T15:49:21Z (GMT). No. of bitstreams: 2 SHARMAPRIYADARSHINI-THESIS-2017.pdf: 3818021 bytes, checksum: 364db318a92dd4010efe1a812ac4dbfe (MD5) LICENSE.txt: 4227 bytes, checksum: 86099e882ada3e7bc9724c7347c6bbc9 (MD5) Previous issue date: 2017-12-15"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Maximum entropy quadratic model to characterize chemical non-equilibrium in re-entry flows"]}]}],"canonical_facts":{"dc:contributor":["Panesi, Marco"],"dc:creator":["Sharma Priyadarshini, Maitreyee"],"dc:date":["2018-03-13T15:49:21Z","2017-12-15","2017-12"],"dc:description":["This thesis presents the study of an advanced non-equilibrium model for state-specific chemical kinetics based on method of moments. The focus of this project is on the rovibrational chemical kinetics of the N2-N system. Internal excitation, dissociation, recombination and energy transfer reactions, which are important processes in aerothermodynamics, are studied. The kinetic and thermodynamic data is obtained from ab-initio calculations performed at NASA Ames Research Center. Previous analysis of the population distribution revealed that the population of the low lying energy levels of nitrogen molecules strongly deviates from a Boltzmann distribution, and the non-equilibrium distribution exhibits significant curvature. By invoking the maximum entropy principle subject to a series of constraints, the logarithm of distribution function is reconstructed using quadratic functions in the internal energy space of the molecular species. The results of the numerical simulations for an ideal chemical reactor show that the quadratic model captures the excitation and dissociation profiles accurately by using only three to seven groups thereby reducing the computational costs for non-equilibrium flow simulations significantly.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2018-03-13 without embargo terms","The student, Maitreyee Sharma Priyadarshini, accepted the attached license on 2017-12-14 at 14:02.","The student, Maitreyee Sharma Priyadarshini, submitted this Thesis for approval on 2017-12-15 at 09:28.","This Thesis was approved for publication on 2017-12-15 at 11:18.","DSpace SAF Submission Ingestion Package generated from Vireo submission #11982 on 2018-03-13 at 10:12:50","Made available in DSpace on 2018-03-13T15:49:21Z (GMT). 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