{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/78793"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/78793","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Propagation of spherically expanding premixed flames","abstract":"The propagation of spherically expanding premixed flames is investigated, in both confined and unconfined scenarios. In the unconfined case, the flame propagates at nearly isobaric conditions and the flame displacement speed eventually reaches a constant value whereas in the confined case there is pressure buildup which affects the flame displacement speed which increases as the flame grows larger. In the confined case, the evolution of the flame with time is studied with emphasis on properties like pressure as a function of time, temperature and velocity field in the channel and the displacement speed. The temperature profiles over the domain are obtained which give an idea about the flame thickness at that instant in time. Effect of the Lewis number on the behavior of the flame is examined in the unconfined scenario. Also, the effect of stretch rate on local density weighted flame displacement speeds is studied, which indicates toward the consistent definition of the flame displacement speed. The numerical results are compared with a non-linear analytical model that treats the flame as a density discontinuity. This model requires only solving the hydro dynamic equations along with the appropriate jump conditions across the flame front. The main difference between the numerical and the analytical solution is that the numerical solution takes into consideration a finite rate chemistry throughout the domain whereas in the analytical solution the reaction rate is modeled as a delta function. Similarities and differences between the analytical and the numerical solution are studied.","abstract_html":"The propagation of spherically expanding premixed flames is investigated, in both confined and unconfined scenarios. In the unconfined case, the flame propagates at nearly isobaric conditions and the flame displacement speed eventually reaches a constant value whereas in the confined case there is pressure buildup which affects the flame displacement speed which increases as the flame grows larger. In the confined case, the evolution of the flame with time is studied with emphasis on properties like pressure as a function of time, temperature and velocity field in the channel and the displacement speed. The temperature profiles over the domain are obtained which give an idea about the flame thickness at that instant in time. Effect of the Lewis number on the behavior of the flame is examined in the unconfined scenario. Also, the effect of stretch rate on local density weighted flame displacement speeds is studied, which indicates toward the consistent definition of the flame displacement speed. The numerical results are compared with a non-linear analytical model that treats the flame as a density discontinuity. This model requires only solving the hydro dynamic equations along with the appropriate jump conditions across the flame front. The main difference between the numerical and the analytical solution is that the numerical solution takes into consideration a finite rate chemistry throughout the domain whereas in the analytical solution the reaction rate is modeled as a delta function. Similarities and differences between the analytical and the numerical solution are studied.","abstract_has_math":false,"creators":["Lokhande, Omkar"],"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":"2015-07-22T22:46:06Z","date_published":"2015-07-22T22:46:06Z","updated_at":"2026-07-22T22:26:12Z","subjects":["premixed flames","spherically symmetric"],"languages":["en"],"rights":["Copyright 2015 Omkar Lokhande"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/78793","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Lokhande, Omkar"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-07-22T22:46:06Z","2017-07-23T09:15:17Z","2015-05","2015-04-29","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":["premixed flames","spherically symmetric"]}]},{"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 Omkar Lokhande"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/78793"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The propagation of spherically expanding premixed flames is investigated, in both confined and unconfined scenarios. In the unconfined case, the flame propagates at nearly isobaric conditions and the flame displacement speed eventually reaches a constant value whereas in the confined case there is pressure buildup which affects the flame displacement speed which increases as the flame grows larger. In the confined case, the evolution of the flame with time is studied with emphasis on properties like pressure as a function of time, temperature and velocity field in the channel and the displacement speed. The temperature profiles over the domain are obtained which give an idea about the flame thickness at that instant in time. Effect of the Lewis number on the behavior of the flame is examined in the unconfined scenario. Also, the effect of stretch rate on local density weighted flame displacement speeds is studied, which indicates toward the consistent definition of the flame displacement speed. The numerical results are compared with a non-linear analytical model that treats the flame as a density discontinuity. This model requires only solving the hydro dynamic equations along with the appropriate jump conditions across the flame front. The main difference between the numerical and the analytical solution is that the numerical solution takes into consideration a finite rate chemistry throughout the domain whereas in the analytical solution the reaction rate is modeled as a delta function. Similarities and differences between the analytical and the numerical solution are studied.","Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2017-05-01","The student, Omkar Lokhande, accepted the attached license on 2015-04-28 at 12:29.","The student, Omkar Lokhande, submitted this Thesis for approval on 2015-04-28 at 12:40.","This Thesis was approved for publication on 2015-04-29 at 15:44.","DSpace SAF Submission Ingestion Package generated from Vireo submission #8156 on 2015-07-22 at 14:26:32","Made available in DSpace on 2015-07-22T22:46:06Z (GMT). No. of bitstreams: 2 LOKHANDE-THESIS-2015.pdf: 1939170 bytes, checksum: 24bec485799535ed19ca0cfa0e7e6381 (MD5) LICENSE.txt: 4211 bytes, checksum: 6b1333cdfd57da844ee37ed1186dfd33 (MD5) Previous issue date: 2015-04-29","Embargo set by: Seth Robbins for item 80034 Lift date: 2017-07-22T22:46:21Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system","Limited Restriction Lifted for Item 80034 on 2017-07-23T09:15:17Z."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Propagation of spherically expanding premixed flames"]}]}],"canonical_facts":{"dc:creator":["Lokhande, Omkar"],"dc:date":["2015-07-22T22:46:06Z","2017-07-23T09:15:17Z","2015-05","2015-04-29","2015-5"],"dc:description":["The propagation of spherically expanding premixed flames is investigated, in both confined and unconfined scenarios. In the unconfined case, the flame propagates at nearly isobaric conditions and the flame displacement speed eventually reaches a constant value whereas in the confined case there is pressure buildup which affects the flame displacement speed which increases as the flame grows larger. In the confined case, the evolution of the flame with time is studied with emphasis on properties like pressure as a function of time, temperature and velocity field in the channel and the displacement speed. The temperature profiles over the domain are obtained which give an idea about the flame thickness at that instant in time. Effect of the Lewis number on the behavior of the flame is examined in the unconfined scenario. Also, the effect of stretch rate on local density weighted flame displacement speeds is studied, which indicates toward the consistent definition of the flame displacement speed. The numerical results are compared with a non-linear analytical model that treats the flame as a density discontinuity. This model requires only solving the hydro dynamic equations along with the appropriate jump conditions across the flame front. The main difference between the numerical and the analytical solution is that the numerical solution takes into consideration a finite rate chemistry throughout the domain whereas in the analytical solution the reaction rate is modeled as a delta function. Similarities and differences between the analytical and the numerical solution are studied.","Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2017-05-01","The student, Omkar Lokhande, accepted the attached license on 2015-04-28 at 12:29.","The student, Omkar Lokhande, submitted this Thesis for approval on 2015-04-28 at 12:40.","This Thesis was approved for publication on 2015-04-29 at 15:44.","DSpace SAF Submission Ingestion Package generated from Vireo submission #8156 on 2015-07-22 at 14:26:32","Made available in DSpace on 2015-07-22T22:46:06Z (GMT). No. of bitstreams: 2 LOKHANDE-THESIS-2015.pdf: 1939170 bytes, checksum: 24bec485799535ed19ca0cfa0e7e6381 (MD5) LICENSE.txt: 4211 bytes, checksum: 6b1333cdfd57da844ee37ed1186dfd33 (MD5) Previous issue date: 2015-04-29","Embargo set by: Seth Robbins for item 80034 Lift date: 2017-07-22T22:46:21Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system","Limited Restriction Lifted for Item 80034 on 2017-07-23T09:15:17Z."],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/78793"],"dc:language":["en"],"dc:rights":["Copyright 2015 Omkar Lokhande"],"dc:subject":["premixed flames","spherically symmetric"],"dc:title":["Propagation of spherically expanding premixed 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":"2026-07-22T22:26:12Z"}