{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/44388"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/44388","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Experimental determination of strain rates in stretched laminar diffusion flames","abstract":"A laser Doppler anemometer was used to measure the axial and radial velocity components of hydrogen-air counterflow diffusion flames (CFDF). An axisymmetric opposed jet burner (OJB) used seeded air in one cylindrical tube, and a hydrogen-nitrogen mixture in the opposing cylindrical tube. Velocity measurements were made at four different operating flow rates, and were used to compute the associated strain rate fields. The results were used to qualitatively assess current CFDF modeling schemes, and to expand the knowledge of the fluid velocity field behavior within these flames. The data show behavior qualitatively consistent with most models and experimental studies: the radial velocity is essentially linear with radial position, and the velocity data collapse to functions of axial position only for regions away from the stagnation plane. However, the data also show a variable strain rate field and a relatively thick reaction zone, which are both inconsistent with CFDF models. The axial velocity fields also behaved unexpectedly as the operating flow rates were increased, transitioning from the characteristic N -shaped profile to an asymptotically-approaching profile.","abstract_html":"A laser Doppler anemometer was used to measure the axial and radial velocity components of hydrogen-air counterflow diffusion flames (CFDF). An axisymmetric opposed jet burner (OJB) used seeded air in one cylindrical tube, and a hydrogen-nitrogen mixture in the opposing cylindrical tube. Velocity measurements were made at four different operating flow rates, and were used to compute the associated strain rate fields. The results were used to qualitatively assess current CFDF modeling schemes, and to expand the knowledge of the fluid velocity field behavior within these flames. The data show behavior qualitatively consistent with most models and experimental studies: the radial velocity is essentially linear with radial position, and the velocity data collapse to functions of axial position only for regions away from the stagnation plane. However, the data also show a variable strain rate field and a relatively thick reaction zone, which are both inconsistent with CFDF models. The axial velocity fields also behaved unexpectedly as the operating flow rates were increased, transitioning from the characteristic N -shaped profile to an asymptotically-approaching profile.","abstract_has_math":false,"creators":["Long, Scott R."],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Mechanical Engineering","degree_department":"Mechanical Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Dancey, Clinton L."],"committee_members":["Brown, Eugene F."],"year":1992,"date_issued":"1992-09-05","date_published":"1992-09-05","updated_at":"2026-07-22T22:18:55Z","subjects":[],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-08222009-040351"],"render_values":[{"text":"etd-08222009-040351","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/44388","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Dancey, Clinton L."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Brown, Eugene F."]},{"key":"dc:contributor.department","label":"Department","values":["Mechanical Engineering"]},{"key":"dc:creator","label":"Author","values":["Long, Scott R."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:43:27Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:43:27Z","2009-08-22"]},{"key":"dc:date.issued","label":"Date","values":["1992-09-05"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.dcmitype","label":"Dc Type Dcmitype","values":["Text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-08222009-040351"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/44388"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["A laser Doppler anemometer was used to measure the axial and radial velocity components of hydrogen-air counterflow diffusion flames (CFDF). An axisymmetric opposed jet burner (OJB) used seeded air in one cylindrical tube, and a hydrogen-nitrogen mixture in the opposing cylindrical tube. Velocity measurements were made at four different operating flow rates, and were used to compute the associated strain rate fields. The results were used to qualitatively assess current CFDF modeling schemes, and to expand the knowledge of the fluid velocity field behavior within these flames. The data show behavior qualitatively consistent with most models and experimental studies: the radial velocity is essentially linear with radial position, and the velocity data collapse to functions of axial position only for regions away from the stagnation plane. However, the data also show a variable strain rate field and a relatively thick reaction zone, which are both inconsistent with CFDF models. The axial velocity fields also behaved unexpectedly as the operating flow rates were increased, transitioning from the characteristic N -shaped profile to an asymptotically-approaching profile."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["BTD"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Experimental determination of strain rates in stretched laminar diffusion flames"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Dancey, Clinton L."],"dc:contributor.committeemember":["Brown, Eugene F."],"dc:contributor.department":["Mechanical Engineering"],"dc:creator":["Long, Scott R."],"dc:date.accessioned":["2014-03-14T21:43:27Z"],"dc:date.available":["2014-03-14T21:43:27Z","2009-08-22"],"dc:date.issued":["1992-09-05"],"dc:description.abstract":["A laser Doppler anemometer was used to measure the axial and radial velocity components of hydrogen-air counterflow diffusion flames (CFDF). An axisymmetric opposed jet burner (OJB) used seeded air in one cylindrical tube, and a hydrogen-nitrogen mixture in the opposing cylindrical tube. Velocity measurements were made at four different operating flow rates, and were used to compute the associated strain rate fields. The results were used to qualitatively assess current CFDF modeling schemes, and to expand the knowledge of the fluid velocity field behavior within these flames. The data show behavior qualitatively consistent with most models and experimental studies: the radial velocity is essentially linear with radial position, and the velocity data collapse to functions of axial position only for regions away from the stagnation plane. However, the data also show a variable strain rate field and a relatively thick reaction zone, which are both inconsistent with CFDF models. 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