{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/78555"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/78555","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Studies on counterflow diffusion flames","abstract":"Certain aspects of counterflow diffusion flames are addressed in the context of one-step Arrhenius-type global chemical reaction. The general Large-activation-energy asymptotic theory for diffusion flames is first revised and then applied to one dimensional counterflow diffusion flames with finite separation distance between reactant supplies under constant density assumption. Comparisons are made between solutions for plug flow and for potential flow boundary conditions. Furthermore, the displacement effects of one dimensional counterflow diffusion flames in an infinite domain are studied by solving the governing boundary value problem numerically using Newton's method with a well defined analytical Jacobian. Based on the numerical results, a considerable increase in strain rate at the flame due to thermal expansion is observed, especially for fuel lean conditions. Finally, a potential flow that support a slowly varying two dimensional counterflow diffusion flame is proposed. The location of the curved flame front is determined by asymptotic techniques.","abstract_html":"Certain aspects of counterflow diffusion flames are addressed in the context of one-step Arrhenius-type global chemical reaction. The general Large-activation-energy asymptotic theory for diffusion flames is first revised and then applied to one dimensional counterflow diffusion flames with finite separation distance between reactant supplies under constant density assumption. Comparisons are made between solutions for plug flow and for potential flow boundary conditions. Furthermore, the displacement effects of one dimensional counterflow diffusion flames in an infinite domain are studied by solving the governing boundary value problem numerically using Newton's method with a well defined analytical Jacobian. Based on the numerical results, a considerable increase in strain rate at the flame due to thermal expansion is observed, especially for fuel lean conditions. Finally, a potential flow that support a slowly varying two dimensional counterflow diffusion flame is proposed. The location of the curved flame front is determined by asymptotic techniques.","abstract_has_math":false,"creators":["Li, Lixiang"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-07-22T22:18:11Z","date_published":"2015-07-22T22:18:11Z","updated_at":"2026-07-22T22:26:11Z","subjects":["Counterflow","Diffusion Flames","Large-activation-energy Asymptotic Therory","Displacement Effects","Thermal Expansion","Slowly-varying Flames"],"languages":["en"],"rights":["Copyright 2015 Lixiang Li"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/78555","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Li, Lixiang"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-07-22T22:18:11Z","2015-05","2015-05-01","2015-5"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical 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":["Counterflow","Diffusion Flames","Large-activation-energy Asymptotic Therory","Displacement Effects","Thermal Expansion","Slowly-varying Flames"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2015 Lixiang Li"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/78555"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Certain aspects of counterflow diffusion flames are addressed in the context of one-step Arrhenius-type global chemical reaction. The general Large-activation-energy asymptotic theory for diffusion flames is first revised and then applied to one dimensional counterflow diffusion flames with finite separation distance between reactant supplies under constant density assumption. Comparisons are made between solutions for plug flow and for potential flow boundary conditions. Furthermore, the displacement effects of one dimensional counterflow diffusion flames in an infinite domain are studied by solving the governing boundary value problem numerically using Newton's method with a well defined analytical Jacobian. Based on the numerical results, a considerable increase in strain rate at the flame due to thermal expansion is observed, especially for fuel lean conditions. Finally, a potential flow that support a slowly varying two dimensional counterflow diffusion flame is proposed. The location of the curved flame front is determined by asymptotic techniques.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2015-07-22 without embargo terms","The student, Lixiang Li, accepted the attached license on 2015-04-30 at 18:31.","The student, Lixiang Li, submitted this Thesis for approval on 2015-04-30 at 18:32.","This Thesis was approved for publication on 2015-05-01 at 07:36.","DSpace SAF Submission Ingestion Package generated from Vireo submission #8204 on 2015-07-22 at 10:34:58","Made available in DSpace on 2015-07-22T22:18:11Z (GMT). No. of bitstreams: 2 LI-THESIS-2015.pdf: 5200853 bytes, checksum: cacd43e8544209a153711a4e105cd790 (MD5) LICENSE.txt: 4207 bytes, checksum: f63a5b9188f2f6b5d48136058920849a (MD5) Previous issue date: 2015-05-01"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Studies on counterflow diffusion flames"]}]}],"canonical_facts":{"dc:creator":["Li, Lixiang"],"dc:date":["2015-07-22T22:18:11Z","2015-05","2015-05-01","2015-5"],"dc:description":["Certain aspects of counterflow diffusion flames are addressed in the context of one-step Arrhenius-type global chemical reaction. The general Large-activation-energy asymptotic theory for diffusion flames is first revised and then applied to one dimensional counterflow diffusion flames with finite separation distance between reactant supplies under constant density assumption. Comparisons are made between solutions for plug flow and for potential flow boundary conditions. Furthermore, the displacement effects of one dimensional counterflow diffusion flames in an infinite domain are studied by solving the governing boundary value problem numerically using Newton's method with a well defined analytical Jacobian. Based on the numerical results, a considerable increase in strain rate at the flame due to thermal expansion is observed, especially for fuel lean conditions. Finally, a potential flow that support a slowly varying two dimensional counterflow diffusion flame is proposed. The location of the curved flame front is determined by asymptotic techniques.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2015-07-22 without embargo terms","The student, Lixiang Li, accepted the attached license on 2015-04-30 at 18:31.","The student, Lixiang Li, submitted this Thesis for approval on 2015-04-30 at 18:32.","This Thesis was approved for publication on 2015-05-01 at 07:36.","DSpace SAF Submission Ingestion Package generated from Vireo submission #8204 on 2015-07-22 at 10:34:58","Made available in DSpace on 2015-07-22T22:18:11Z (GMT). No. of bitstreams: 2 LI-THESIS-2015.pdf: 5200853 bytes, checksum: cacd43e8544209a153711a4e105cd790 (MD5) LICENSE.txt: 4207 bytes, checksum: f63a5b9188f2f6b5d48136058920849a (MD5) Previous issue date: 2015-05-01"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/78555"],"dc:language":["en"],"dc:rights":["Copyright 2015 Lixiang Li"],"dc:subject":["Counterflow","Diffusion Flames","Large-activation-energy Asymptotic Therory","Displacement Effects","Thermal Expansion","Slowly-varying Flames"],"dc:title":["Studies on counterflow diffusion flames"],"dc:type":["text"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:11Z"}