{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/44369"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/44369","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Experimental investigation of normal, sonic injection through a wedge-shaped nozzle into supersonic flow","abstract":"An experimental evaluation of normal, sonic, helium injection from a wedgeshaped nozzle and a circular nozzle into a Mach 3 free stream with a total pressure of 6.5 atm and a total temperature of 294 K was conducted. The expansion ratio and the mass rate of flow of both nozzles were matched in order to determine the effect of the geometric difference only. 'Decay rate, penetration, and jet area growth rate were used to compare the mixing performance of the nozzles. Oil flow photography was used to determine the size of the three-dimensional boundary layer separation zone in front of each nozzle, and nanoshadowgraph photography was used to visualize the system of shocks and the flow field of each nozzle. Mean flow quantity profiles at several lateral stations were made at three downstream locations. The profiles were used to calculate helium concentration, Mach number, static temperature, static pressure, density, flow velocity, local speed of sound, mass flux, and total pressure. The two nozzles were then compared on the basis of maximum helium concentration decay, core center and overall penetration, and the growth rate and centroid penetration of a defined jet area. Although the decay rate of the jet from the circular nozzle was slightly higher than the decay rate of the jet from the wedge-shaped nozzle, the mixing performance of the wedge-shaped nozzle exceeded that of the circular nozzle in all other comparison parameters. The jet from the wedge-shaped nozzle penetrated further and its area grew more rapidly than the same parameters for the jet from the circular nozzle. The oil flow photography showed that the wedge-shaped nozzle also had no separation zone in front of it, whereas the circular nozzle had a large separation zone. A separation zone in front of a fuel injector in a scramjet engine can result in damage to the combustor from the extreme heat fluxes to the wall. Also, the total pressure loss in the combustor should be lower for fuel injection through a wedge-shaped nozzle due to the elimination of the normal shock. It was concluded that wedge-shaped fuel injectors should perform better than circular fuel injectors in supersonic combustors.","abstract_html":"An experimental evaluation of normal, sonic, helium injection from a wedgeshaped nozzle and a circular nozzle into a Mach 3 free stream with a total pressure of 6.5 atm and a total temperature of 294 K was conducted. The expansion ratio and the mass rate of flow of both nozzles were matched in order to determine the effect of the geometric difference only. 'Decay rate, penetration, and jet area growth rate were used to compare the mixing performance of the nozzles. Oil flow photography was used to determine the size of the three-dimensional boundary layer separation zone in front of each nozzle, and nanoshadowgraph photography was used to visualize the system of shocks and the flow field of each nozzle. Mean flow quantity profiles at several lateral stations were made at three downstream locations. The profiles were used to calculate helium concentration, Mach number, static temperature, static pressure, density, flow velocity, local speed of sound, mass flux, and total pressure. The two nozzles were then compared on the basis of maximum helium concentration decay, core center and overall penetration, and the growth rate and centroid penetration of a defined jet area. Although the decay rate of the jet from the circular nozzle was slightly higher than the decay rate of the jet from the wedge-shaped nozzle, the mixing performance of the wedge-shaped nozzle exceeded that of the circular nozzle in all other comparison parameters. The jet from the wedge-shaped nozzle penetrated further and its area grew more rapidly than the same parameters for the jet from the circular nozzle. The oil flow photography showed that the wedge-shaped nozzle also had no separation zone in front of it, whereas the circular nozzle had a large separation zone. A separation zone in front of a fuel injector in a scramjet engine can result in damage to the combustor from the extreme heat fluxes to the wall. Also, the total pressure loss in the combustor should be lower for fuel injection through a wedge-shaped nozzle due to the elimination of the normal shock. It was concluded that wedge-shaped fuel injectors should perform better than circular fuel injectors in supersonic combustors.","abstract_has_math":false,"creators":["Barber, Matthew James"],"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":["Roe, Larry A."],"committee_members":["Schetz, Joseph A.","Ng, Fai"],"year":1991,"date_issued":"1991-01-17","date_published":"1991-01-17","updated_at":"2026-07-22T22:20:25Z","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-08222009-040226"],"render_values":[{"text":"etd-08222009-040226","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/44369","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Roe, Larry A."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Schetz, Joseph A.","Ng, Fai"]},{"key":"dc:contributor.department","label":"Department","values":["Mechanical Engineering"]},{"key":"dc:creator","label":"Author","values":["Barber, Matthew James"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:43:19Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:43:19Z","2009-08-22"]},{"key":"dc:date.issued","label":"Date","values":["1991-01-17"]},{"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-08222009-040226"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/44369"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["An experimental evaluation of normal, sonic, helium injection from a wedgeshaped nozzle and a circular nozzle into a Mach 3 free stream with a total pressure of 6.5 atm and a total temperature of 294 K was conducted. The expansion ratio and the mass rate of flow of both nozzles were matched in order to determine the effect of the geometric difference only. 'Decay rate, penetration, and jet area growth rate were used to compare the mixing performance of the nozzles. Oil flow photography was used to determine the size of the three-dimensional boundary layer separation zone in front of each nozzle, and nanoshadowgraph photography was used to visualize the system of shocks and the flow field of each nozzle. Mean flow quantity profiles at several lateral stations were made at three downstream locations. The profiles were used to calculate helium concentration, Mach number, static temperature, static pressure, density, flow velocity, local speed of sound, mass flux, and total pressure. The two nozzles were then compared on the basis of maximum helium concentration decay, core center and overall penetration, and the growth rate and centroid penetration of a defined jet area. Although the decay rate of the jet from the circular nozzle was slightly higher than the decay rate of the jet from the wedge-shaped nozzle, the mixing performance of the wedge-shaped nozzle exceeded that of the circular nozzle in all other comparison parameters. The jet from the wedge-shaped nozzle penetrated further and its area grew more rapidly than the same parameters for the jet from the circular nozzle. The oil flow photography showed that the wedge-shaped nozzle also had no separation zone in front of it, whereas the circular nozzle had a large separation zone. A separation zone in front of a fuel injector in a scramjet engine can result in damage to the combustor from the extreme heat fluxes to the wall. Also, the total pressure loss in the combustor should be lower for fuel injection through a wedge-shaped nozzle due to the elimination of the normal shock. It was concluded that wedge-shaped fuel injectors should perform better than circular fuel injectors in supersonic combustors."]},{"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 investigation of normal, sonic injection through a wedge-shaped nozzle into supersonic flow"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Roe, Larry A."],"dc:contributor.committeemember":["Schetz, Joseph A.","Ng, Fai"],"dc:contributor.department":["Mechanical Engineering"],"dc:creator":["Barber, Matthew James"],"dc:date.accessioned":["2014-03-14T21:43:19Z"],"dc:date.available":["2014-03-14T21:43:19Z","2009-08-22"],"dc:date.issued":["1991-01-17"],"dc:description.abstract":["An experimental evaluation of normal, sonic, helium injection from a wedgeshaped nozzle and a circular nozzle into a Mach 3 free stream with a total pressure of 6.5 atm and a total temperature of 294 K was conducted. The expansion ratio and the mass rate of flow of both nozzles were matched in order to determine the effect of the geometric difference only. 'Decay rate, penetration, and jet area growth rate were used to compare the mixing performance of the nozzles. Oil flow photography was used to determine the size of the three-dimensional boundary layer separation zone in front of each nozzle, and nanoshadowgraph photography was used to visualize the system of shocks and the flow field of each nozzle. Mean flow quantity profiles at several lateral stations were made at three downstream locations. The profiles were used to calculate helium concentration, Mach number, static temperature, static pressure, density, flow velocity, local speed of sound, mass flux, and total pressure. The two nozzles were then compared on the basis of maximum helium concentration decay, core center and overall penetration, and the growth rate and centroid penetration of a defined jet area. Although the decay rate of the jet from the circular nozzle was slightly higher than the decay rate of the jet from the wedge-shaped nozzle, the mixing performance of the wedge-shaped nozzle exceeded that of the circular nozzle in all other comparison parameters. The jet from the wedge-shaped nozzle penetrated further and its area grew more rapidly than the same parameters for the jet from the circular nozzle. The oil flow photography showed that the wedge-shaped nozzle also had no separation zone in front of it, whereas the circular nozzle had a large separation zone. A separation zone in front of a fuel injector in a scramjet engine can result in damage to the combustor from the extreme heat fluxes to the wall. Also, the total pressure loss in the combustor should be lower for fuel injection through a wedge-shaped nozzle due to the elimination of the normal shock. It was concluded that wedge-shaped fuel injectors should perform better than circular fuel injectors in supersonic combustors."],"dc:description.degree":["Master of Science"],"dc:format.medium":["BTD"],"dc:format.mimetype":["application/pdf"],"dc:identifier.other":["etd-08222009-040226"],"dc:identifier.uri":["http://hdl.handle.net/10919/44369"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["Experimental investigation of normal, sonic injection through a wedge-shaped nozzle into supersonic flow"],"dc:type":["Thesis"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:25Z"}