{"id":{"repo_id":"uwo","oai_identifier":"oai:uwo.scholaris.ca:20.500.14721/31035"},"canonical_url":"https://search.dev.ndltd.org/etd/uwo/oai:uwo.scholaris.ca:20.500.14721/31035","repository":{"repo_id":"uwo","name":"Western University","base_url":"https://uwo.scholaris.ca/server/oai/request"},"display":{"title":"Flow Visualization Study of Wake-Stabilized Diffusion Flames in a Crossflow: Effects of Crossflow Turbulence","abstract":"Effects of crosswind turbulence on the mechanisms and flow structures affecting emissions from non-premixed wake stabilized flames from elevated stacks are investigated. In the current work, two conditions of upstream crossflow are tested to investigate the effects of turbulence on the flame, including the turbulent flow with enhanced freestream turbulence that is generated by a passive grid placed upstream of the burner, and smooth flow with ambient turbulence for baseline comparisons. The experimental method of Mie scattering flow visualization is used to investigate the effects of turbulence. The addition of freestream turbulence has been found to make changes to the flame characteristics and the development of vortical structures in the separated shear layer, which are closely associated with increases in combustion inefficiency. The fuel stripping mechanism was proposed to be responsible for inefficient combustion; a few bits of unburnt fuels are observed to be drawn through adjacent flame pockets, and finally are ejected away from the underside of flame without combustion. The Mie scattering images combined with combustion inefficiency data indicated the bypass-transition in the shear layer plays an important role in the fuel stripping mechanism.","abstract_html":"Effects of crosswind turbulence on the mechanisms and flow structures affecting emissions from non-premixed wake stabilized flames from elevated stacks are investigated. In the current work, two conditions of upstream crossflow are tested to investigate the effects of turbulence on the flame, including the turbulent flow with enhanced freestream turbulence that is generated by a passive grid placed upstream of the burner, and smooth flow with ambient turbulence for baseline comparisons. The experimental method of Mie scattering flow visualization is used to investigate the effects of turbulence. The addition of freestream turbulence has been found to make changes to the flame characteristics and the development of vortical structures in the separated shear layer, which are closely associated with increases in combustion inefficiency. The fuel stripping mechanism was proposed to be responsible for inefficient combustion; a few bits of unburnt fuels are observed to be drawn through adjacent flame pockets, and finally are ejected away from the underside of flame without combustion. The Mie scattering images combined with combustion inefficiency data indicated the bypass-transition in the shear layer plays an important role in the fuel stripping mechanism.","abstract_has_math":false,"creators":["Cui, Diya"],"institution":"The University of Western Ontario","degree_name":"M Sc","degree_level":null,"degree_discipline":"Civil and Environmental Engineering","degree_department":null,"school":null,"contributors":[],"advisors":["Kopp, Gregory A."],"committee_chairs":[],"committee_members":[],"year":2021,"date_issued":"2021-04-15","date_published":"2021-04-15","updated_at":"2026-07-27T21:56:16Z","subjects":["Freestream turbulence","non-premixed flame","Mie scattering flow visualization","separated shear layers","gas flares."],"languages":["en_ca"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/20.500.14721/31035","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Kopp, Gregory A."]},{"key":"dc:creator","label":"Author","values":["Cui, Diya"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2025-07-10T18:49:59Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2025-07-10T18:49:59Z"]},{"key":"dc:date.issued","label":"Date","values":["2021-04-15"]},{"key":"dc:publisher","label":"Institution","values":["The University of Western Ontario"]},{"key":"dc:type","label":"Dc Type","values":["thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Civil and Environmental Engineering"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M Sc"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Freestream turbulence","non-premixed flame","Mie scattering flow visualization","separated shear layers","gas flares."]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_ca"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/20.500.14721/31035"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The thesis cover page in the PDF document includes references to Western University’s previous institutional repository platform, known as Scholarship@Western, and links to that platform (beginning with ir.lib.uwo.ca). In citing or referring to this thesis, use the DOI or handle from this page instead. Sample citation: Author name, \"Thesis title.\" (Year). Western University Open Repository. https://doi.org/10.71858/123456."]},{"key":"dc:description.abstract","label":"Abstract","values":["Effects of crosswind turbulence on the mechanisms and flow structures affecting emissions from non-premixed wake stabilized flames from elevated stacks are investigated. In the current work, two conditions of upstream crossflow are tested to investigate the effects of turbulence on the flame, including the turbulent flow with enhanced freestream turbulence that is generated by a passive grid placed upstream of the burner, and smooth flow with ambient turbulence for baseline comparisons. The experimental method of Mie scattering flow visualization is used to investigate the effects of turbulence. The addition of freestream turbulence has been found to make changes to the flame characteristics and the development of vortical structures in the separated shear layer, which are closely associated with increases in combustion inefficiency. The fuel stripping mechanism was proposed to be responsible for inefficient combustion; a few bits of unburnt fuels are observed to be drawn through adjacent flame pockets, and finally are ejected away from the underside of flame without combustion. The Mie scattering images combined with combustion inefficiency data indicated the bypass-transition in the shear layer plays an important role in the fuel stripping mechanism."]},{"key":"dc:title","label":"Title","values":["Flow Visualization Study of Wake-Stabilized Diffusion Flames in a Crossflow: Effects of Crossflow Turbulence"]}]}],"canonical_facts":{"dc:contributor.advisor":["Kopp, Gregory A."],"dc:creator":["Cui, Diya"],"dc:date.accessioned":["2025-07-10T18:49:59Z"],"dc:date.available":["2025-07-10T18:49:59Z"],"dc:date.issued":["2021-04-15"],"dc:description":["The thesis cover page in the PDF document includes references to Western University’s previous institutional repository platform, known as Scholarship@Western, and links to that platform (beginning with ir.lib.uwo.ca). In citing or referring to this thesis, use the DOI or handle from this page instead. Sample citation: Author name, \"Thesis title.\" (Year). Western University Open Repository. https://doi.org/10.71858/123456."],"dc:description.abstract":["Effects of crosswind turbulence on the mechanisms and flow structures affecting emissions from non-premixed wake stabilized flames from elevated stacks are investigated. In the current work, two conditions of upstream crossflow are tested to investigate the effects of turbulence on the flame, including the turbulent flow with enhanced freestream turbulence that is generated by a passive grid placed upstream of the burner, and smooth flow with ambient turbulence for baseline comparisons. The experimental method of Mie scattering flow visualization is used to investigate the effects of turbulence. The addition of freestream turbulence has been found to make changes to the flame characteristics and the development of vortical structures in the separated shear layer, which are closely associated with increases in combustion inefficiency. The fuel stripping mechanism was proposed to be responsible for inefficient combustion; a few bits of unburnt fuels are observed to be drawn through adjacent flame pockets, and finally are ejected away from the underside of flame without combustion. The Mie scattering images combined with combustion inefficiency data indicated the bypass-transition in the shear layer plays an important role in the fuel stripping mechanism."],"dc:identifier.uri":["https://hdl.handle.net/20.500.14721/31035"],"dc:language.iso":["en_ca"],"dc:publisher":["The University of Western Ontario"],"dc:subject":["Freestream turbulence","non-premixed flame","Mie scattering flow visualization","separated shear layers","gas flares."],"dc:title":["Flow Visualization Study of Wake-Stabilized Diffusion Flames in a Crossflow: Effects of Crossflow Turbulence"],"dc:type":["thesis"],"thesis:degree_discipline":["Civil and Environmental Engineering"],"thesis:degree_name":["M Sc"]},"updated_at":"2026-07-27T21:56:16Z"}