{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:62559"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:62559","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Bildgebende Multiparameter-Lasermessungen in komplexen technischen Strömungs- und Verbrennungsprozessen","abstract":"In this work the origin of cycle-to-cycle fluctuations of an air guided combustion process is investigated experimentally by means of laser diagnostics. A multi-parameter measurement technique is developed, which allows for the simultaneous, instantaneous and planar detection of five quantities that are relevant to the mixture preparation process. The basis of the multi-parameter measurement technique is an exciplex tracer that enables the spectral separation of the signals from the liquid and the vapor phase, respectively. The temperature distribution of the liquid phase is measured via 2-line thermometry. That, with the aid of the liquid temperature crosstalk corrected vapor phase signal, is quantified by an homogeneous calibration charge. The flow fields of both phases are measured simultaneously to the fuel distribution using spatial inhomogeneities that are inherent to the spray. The spray structure is measured twice via double pulse excitation and detection and reduced by the GIV algorithm. In addition to the fuel distribution and the liquid temperature distribution this set-up enables for the first time, together with the spectral separation of the signals, a particle-free, simultaneous measurement of the liquid and vapor phase flow fields inside the combustion chamber of a fired DISI engine. The measurements reveal that misfires are primarily caused by overly lean conditions at the spark plug at spark timing. The simultaneously measured flow fields of the liquid and vaporized fuel show that the faster leaning of the misfiring cycles is caused by higher vapor phase velocities that are induced by the in-cylinder air flow and not by the injection. Furthermore this work deals with the basic structure of hydrocarbon diffusion flames. Stationary curved diffusion flames are established using a modified counterflow burner and investigated by laser diagnostics. Methane, propane and n-butane are used. The structure of the reaction zone is visualized by means of OH-LIPF and that of the sooting zone is measured semi-quantitatively via LII. The extinction limits as a function of the flame curvature are determined. At the extinction limit the structure of the curved flame is strongly influenced by the orientation of curvature towards the higher diffusive component participating in the combustion. To investigate the influence of preferential diffusion and flame curvature on the soot behaviour, the oxygen fraction, the orientation and strength of curvature, and the orientation of gravity are varied. It reveals that the soot concentration is less influenced by the orientation of curvature rather than if it is located above or below the reaction zone. The flame temperature is another important parameter for the soot volume fraction, which is shown by the variation of the oxygen concentration. When increasing flame temperatures the soot volume fraction increases strongly. The influence of preferential diffusion and flame curvature on the soot formation is superposed by the gravity and/or buoyancy effects and by the strong temperature dependence. Nevertheless the fuel specific effects can be explained by preferential diffusion and flame curvature.","abstract_html":"In this work the origin of cycle-to-cycle fluctuations of an air guided combustion process is investigated experimentally by means of laser diagnostics. A multi-parameter measurement technique is developed, which allows for the simultaneous, instantaneous and planar detection of five quantities that are relevant to the mixture preparation process. The basis of the multi-parameter measurement technique is an exciplex tracer that enables the spectral separation of the signals from the liquid and the vapor phase, respectively. The temperature distribution of the liquid phase is measured via 2-line thermometry. That, with the aid of the liquid temperature crosstalk corrected vapor phase signal, is quantified by an homogeneous calibration charge. The flow fields of both phases are measured simultaneously to the fuel distribution using spatial inhomogeneities that are inherent to the spray. The spray structure is measured twice via double pulse excitation and detection and reduced by the GIV algorithm. In addition to the fuel distribution and the liquid temperature distribution this set-up enables for the first time, together with the spectral separation of the signals, a particle-free, simultaneous measurement of the liquid and vapor phase flow fields inside the combustion chamber of a fired DISI engine. The measurements reveal that misfires are primarily caused by overly lean conditions at the spark plug at spark timing. The simultaneously measured flow fields of the liquid and vaporized fuel show that the faster leaning of the misfiring cycles is caused by higher vapor phase velocities that are induced by the in-cylinder air flow and not by the injection. Furthermore this work deals with the basic structure of hydrocarbon diffusion flames. Stationary curved diffusion flames are established using a modified counterflow burner and investigated by laser diagnostics. Methane, propane and n-butane are used. The structure of the reaction zone is visualized by means of OH-LIPF and that of the sooting zone is measured semi-quantitatively via LII. The extinction limits as a function of the flame curvature are determined. At the extinction limit the structure of the curved flame is strongly influenced by the orientation of curvature towards the higher diffusive component participating in the combustion. To investigate the influence of preferential diffusion and flame curvature on the soot behaviour, the oxygen fraction, the orientation and strength of curvature, and the orientation of gravity are varied. It reveals that the soot concentration is less influenced by the orientation of curvature rather than if it is located above or below the reaction zone. The flame temperature is another important parameter for the soot volume fraction, which is shown by the variation of the oxygen concentration. When increasing flame temperatures the soot volume fraction increases strongly. The influence of preferential diffusion and flame curvature on the soot formation is superposed by the gravity and/or buoyancy effects and by the strong temperature dependence. Nevertheless the fuel specific effects can be explained by preferential diffusion and flame curvature.","abstract_has_math":false,"creators":["Wieske, Peter"],"institution":"Publikationsserver der RWTH Aachen University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Peters, Norbert"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2007,"date_issued":"2007","date_published":"2007","updated_at":"2026-07-30T19:43:28Z","subjects":["info:eu-repo/classification/ddc/620","Optische Messtechnik","Laserinduzierte Fluoreszenz","Strömungsmesstechnik","Verbrennungsmotor","Diffusionsflamme","Ingenieurwissenschaften","Zyklische Schwankungen","differentielle Diffusion","LIEF","LIPF","LII","cyclic fluctuations","preferential diffusion"],"languages":["ger"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-124123%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-124123%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-124123%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/62559","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Peters, Norbert"]},{"key":"dc:creator","label":"Author","values":["Wieske, Peter"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:coverage","label":"Dc Coverage","values":["DE"]},{"key":"dc:date","label":"Dc Date","values":["2007"]},{"key":"dc:publisher","label":"Institution","values":["Publikationsserver der RWTH Aachen University"]},{"key":"dc:relation","label":"Dc Relation","values":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-21009"]},{"key":"dc:type","label":"Dc Type","values":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["info:eu-repo/classification/ddc/620","Optische Messtechnik","Laserinduzierte Fluoreszenz","Strömungsmesstechnik","Verbrennungsmotor","Diffusionsflamme","Ingenieurwissenschaften","Zyklische Schwankungen","differentielle Diffusion","LIEF","LIPF","LII","cyclic fluctuations","preferential diffusion"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["ger"]},{"key":"dc:rights","label":"Dc Rights","values":["info:eu-repo/semantics/openAccess"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/record/62559","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-124123%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["In this work the origin of cycle-to-cycle fluctuations of an air guided combustion process is investigated experimentally by means of laser diagnostics. A multi-parameter measurement technique is developed, which allows for the simultaneous, instantaneous and planar detection of five quantities that are relevant to the mixture preparation process. The basis of the multi-parameter measurement technique is an exciplex tracer that enables the spectral separation of the signals from the liquid and the vapor phase, respectively. The temperature distribution of the liquid phase is measured via 2-line thermometry. That, with the aid of the liquid temperature crosstalk corrected vapor phase signal, is quantified by an homogeneous calibration charge. The flow fields of both phases are measured simultaneously to the fuel distribution using spatial inhomogeneities that are inherent to the spray. The spray structure is measured twice via double pulse excitation and detection and reduced by the GIV algorithm. In addition to the fuel distribution and the liquid temperature distribution this set-up enables for the first time, together with the spectral separation of the signals, a particle-free, simultaneous measurement of the liquid and vapor phase flow fields inside the combustion chamber of a fired DISI engine. The measurements reveal that misfires are primarily caused by overly lean conditions at the spark plug at spark timing. The simultaneously measured flow fields of the liquid and vaporized fuel show that the faster leaning of the misfiring cycles is caused by higher vapor phase velocities that are induced by the in-cylinder air flow and not by the injection. Furthermore this work deals with the basic structure of hydrocarbon diffusion flames. Stationary curved diffusion flames are established using a modified counterflow burner and investigated by laser diagnostics. Methane, propane and n-butane are used. The structure of the reaction zone is visualized by means of OH-LIPF and that of the sooting zone is measured semi-quantitatively via LII. The extinction limits as a function of the flame curvature are determined. At the extinction limit the structure of the curved flame is strongly influenced by the orientation of curvature towards the higher diffusive component participating in the combustion. To investigate the influence of preferential diffusion and flame curvature on the soot behaviour, the oxygen fraction, the orientation and strength of curvature, and the orientation of gravity are varied. It reveals that the soot concentration is less influenced by the orientation of curvature rather than if it is located above or below the reaction zone. The flame temperature is another important parameter for the soot volume fraction, which is shown by the variation of the oxygen concentration. When increasing flame temperatures the soot volume fraction increases strongly. The influence of preferential diffusion and flame curvature on the soot formation is superposed by the gravity and/or buoyancy effects and by the strong temperature dependence. Nevertheless the fuel specific effects can be explained by preferential diffusion and flame curvature."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Publikationsserver der RWTH Aachen University XIV, 114 S. : Ill., graph. Darst. (2007). = Aachen, Techn. Hochsch., Diss., 2007"]},{"key":"dc:title","label":"Title","values":["Bildgebende Multiparameter-Lasermessungen in komplexen technischen Strömungs- und Verbrennungsprozessen"]}]}],"canonical_facts":{"dc:contributor":["Peters, Norbert"],"dc:coverage":["DE"],"dc:creator":["Wieske, Peter"],"dc:date":["2007"],"dc:description":["In this work the origin of cycle-to-cycle fluctuations of an air guided combustion process is investigated experimentally by means of laser diagnostics. A multi-parameter measurement technique is developed, which allows for the simultaneous, instantaneous and planar detection of five quantities that are relevant to the mixture preparation process. The basis of the multi-parameter measurement technique is an exciplex tracer that enables the spectral separation of the signals from the liquid and the vapor phase, respectively. The temperature distribution of the liquid phase is measured via 2-line thermometry. That, with the aid of the liquid temperature crosstalk corrected vapor phase signal, is quantified by an homogeneous calibration charge. The flow fields of both phases are measured simultaneously to the fuel distribution using spatial inhomogeneities that are inherent to the spray. The spray structure is measured twice via double pulse excitation and detection and reduced by the GIV algorithm. In addition to the fuel distribution and the liquid temperature distribution this set-up enables for the first time, together with the spectral separation of the signals, a particle-free, simultaneous measurement of the liquid and vapor phase flow fields inside the combustion chamber of a fired DISI engine. The measurements reveal that misfires are primarily caused by overly lean conditions at the spark plug at spark timing. The simultaneously measured flow fields of the liquid and vaporized fuel show that the faster leaning of the misfiring cycles is caused by higher vapor phase velocities that are induced by the in-cylinder air flow and not by the injection. Furthermore this work deals with the basic structure of hydrocarbon diffusion flames. Stationary curved diffusion flames are established using a modified counterflow burner and investigated by laser diagnostics. Methane, propane and n-butane are used. The structure of the reaction zone is visualized by means of OH-LIPF and that of the sooting zone is measured semi-quantitatively via LII. The extinction limits as a function of the flame curvature are determined. At the extinction limit the structure of the curved flame is strongly influenced by the orientation of curvature towards the higher diffusive component participating in the combustion. To investigate the influence of preferential diffusion and flame curvature on the soot behaviour, the oxygen fraction, the orientation and strength of curvature, and the orientation of gravity are varied. It reveals that the soot concentration is less influenced by the orientation of curvature rather than if it is located above or below the reaction zone. The flame temperature is another important parameter for the soot volume fraction, which is shown by the variation of the oxygen concentration. When increasing flame temperatures the soot volume fraction increases strongly. The influence of preferential diffusion and flame curvature on the soot formation is superposed by the gravity and/or buoyancy effects and by the strong temperature dependence. Nevertheless the fuel specific effects can be explained by preferential diffusion and flame curvature."],"dc:identifier":["https://publications.rwth-aachen.de/record/62559","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-124123%22"],"dc:language":["ger"],"dc:publisher":["Publikationsserver der RWTH Aachen University"],"dc:relation":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-21009"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:source":["Aachen : Publikationsserver der RWTH Aachen University XIV, 114 S. : Ill., graph. Darst. (2007). = Aachen, Techn. Hochsch., Diss., 2007"],"dc:subject":["info:eu-repo/classification/ddc/620","Optische Messtechnik","Laserinduzierte Fluoreszenz","Strömungsmesstechnik","Verbrennungsmotor","Diffusionsflamme","Ingenieurwissenschaften","Zyklische Schwankungen","differentielle Diffusion","LIEF","LIPF","LII","cyclic fluctuations","preferential diffusion"],"dc:title":["Bildgebende Multiparameter-Lasermessungen in komplexen technischen Strömungs- und Verbrennungsprozessen"],"dc:type":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]},"updated_at":"2026-07-30T19:43:28Z"}