{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:61483"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:61483","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Zu kohärenten Turbulenzstrukturen in der Strömung gegliederter Gerinne","abstract":"Rivers are an integral part of our environment. Due to different demands in term of utilisation as well as protection an efficient water management is essential. This can only be achieved by a fundamental knowledge of the governing hydro-dynamical processes. In this thesis, the existence of time-dependent organised phenomena, so-called coherent turbulent structures is proved experimentally and these structures are further investigated. A spatial and temporal resolving experimental set-up based on the Particle-Image Velocimetry is used. For detection of the coherent turbulent structures a special method has been developed, which enables to reliable identify the structures and to evaluate them in quantitative matters. Based on this detection-method the regularly appearance of coherent turbulent structures in the shear zone between main channel and adjacent flood plain can be shown. The coherent structures appear to have a three-dimensional shape with a horizontal vortex and a secondary current as their main elements. The internal set-up consists of a vortex core and an outer region which interacts with the surrounding flow field. The coherent turbulent structures are identified to be the dominant flow phenomenon by applying an advanced filter technique to the instantaneous flow fields. Accordingly, the characteristic flow structure in compound channels described by multiple authors- shear zone, secondary currents and high turbulence intensity - can be explained physically by the coherent structures. They also influence the turbulent energy budget by generating a strong production of turbulent kinetic energy within the interaction zone. This net generation of energy is distributed by secondary flows and turbulence fluctuations. The research presented in the thesis on hand could prove the existence of coherent turbulent structures in the shear zone of compound open channels. The appropriate experimental set-up as well as reliable methods have been developed for further studies. Especially a more detailed quantitative description of the structures themselves and also their temporal development are of interest. Based on these results, in the future coherent turbulent structures will be taken into consideration on a physical basis for dealing with practical water management tasks.","abstract_html":"Rivers are an integral part of our environment. Due to different demands in term of utilisation as well as protection an efficient water management is essential. This can only be achieved by a fundamental knowledge of the governing hydro-dynamical processes. In this thesis, the existence of time-dependent organised phenomena, so-called coherent turbulent structures is proved experimentally and these structures are further investigated. A spatial and temporal resolving experimental set-up based on the Particle-Image Velocimetry is used. For detection of the coherent turbulent structures a special method has been developed, which enables to reliable identify the structures and to evaluate them in quantitative matters. Based on this detection-method the regularly appearance of coherent turbulent structures in the shear zone between main channel and adjacent flood plain can be shown. The coherent structures appear to have a three-dimensional shape with a horizontal vortex and a secondary current as their main elements. The internal set-up consists of a vortex core and an outer region which interacts with the surrounding flow field. The coherent turbulent structures are identified to be the dominant flow phenomenon by applying an advanced filter technique to the instantaneous flow fields. Accordingly, the characteristic flow structure in compound channels described by multiple authors- shear zone, secondary currents and high turbulence intensity - can be explained physically by the coherent structures. They also influence the turbulent energy budget by generating a strong production of turbulent kinetic energy within the interaction zone. This net generation of energy is distributed by secondary flows and turbulence fluctuations. The research presented in the thesis on hand could prove the existence of coherent turbulent structures in the shear zone of compound open channels. The appropriate experimental set-up as well as reliable methods have been developed for further studies. Especially a more detailed quantitative description of the structures themselves and also their temporal development are of interest. Based on these results, in the future coherent turbulent structures will be taken into consideration on a physical basis for dealing with practical water management tasks.","abstract_has_math":false,"creators":["von Lukowicz, Joachim"],"institution":"Publikationsserver der RWTH Aachen University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Köngeter, Jürgen"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2003,"date_issued":"2003","date_published":"2003","updated_at":"2026-07-30T19:43:10Z","subjects":["info:eu-repo/classification/ddc/550","Offenes Gerinne","Gerinneströmung","Turbulente Strömung","Kohärenz","Strömungsfeld","Geowissenschaften","Turbulenz","kohärente Strukturen","offene Fließgewässer","PIV","Wirbel"],"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-123144%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123144%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123144%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/61483","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Köngeter, Jürgen"]},{"key":"dc:creator","label":"Author","values":["von Lukowicz, Joachim"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:coverage","label":"Dc Coverage","values":["DE"]},{"key":"dc:date","label":"Dc Date","values":["2003"]},{"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-5282"]},{"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/550","Offenes Gerinne","Gerinneströmung","Turbulente Strömung","Kohärenz","Strömungsfeld","Geowissenschaften","Turbulenz","kohärente Strukturen","offene Fließgewässer","PIV","Wirbel"]}]},{"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/61483","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123144%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Rivers are an integral part of our environment. Due to different demands in term of utilisation as well as protection an efficient water management is essential. This can only be achieved by a fundamental knowledge of the governing hydro-dynamical processes. In this thesis, the existence of time-dependent organised phenomena, so-called coherent turbulent structures is proved experimentally and these structures are further investigated. A spatial and temporal resolving experimental set-up based on the Particle-Image Velocimetry is used. For detection of the coherent turbulent structures a special method has been developed, which enables to reliable identify the structures and to evaluate them in quantitative matters. Based on this detection-method the regularly appearance of coherent turbulent structures in the shear zone between main channel and adjacent flood plain can be shown. The coherent structures appear to have a three-dimensional shape with a horizontal vortex and a secondary current as their main elements. The internal set-up consists of a vortex core and an outer region which interacts with the surrounding flow field. The coherent turbulent structures are identified to be the dominant flow phenomenon by applying an advanced filter technique to the instantaneous flow fields. Accordingly, the characteristic flow structure in compound channels described by multiple authors- shear zone, secondary currents and high turbulence intensity - can be explained physically by the coherent structures. They also influence the turbulent energy budget by generating a strong production of turbulent kinetic energy within the interaction zone. This net generation of energy is distributed by secondary flows and turbulence fluctuations. The research presented in the thesis on hand could prove the existence of coherent turbulent structures in the shear zone of compound open channels. The appropriate experimental set-up as well as reliable methods have been developed for further studies. Especially a more detailed quantitative description of the structures themselves and also their temporal development are of interest. Based on these results, in the future coherent turbulent structures will be taken into consideration on a physical basis for dealing with practical water management tasks."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Publikationsserver der RWTH Aachen University XIV, 147 S. : Ill., graph. Darst. (2003). = Aachen, Techn. Hochsch., Diss., 2002"]},{"key":"dc:title","label":"Title","values":["Zu kohärenten Turbulenzstrukturen in der Strömung gegliederter Gerinne"]}]}],"canonical_facts":{"dc:contributor":["Köngeter, Jürgen"],"dc:coverage":["DE"],"dc:creator":["von Lukowicz, Joachim"],"dc:date":["2003"],"dc:description":["Rivers are an integral part of our environment. Due to different demands in term of utilisation as well as protection an efficient water management is essential. 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The coherent turbulent structures are identified to be the dominant flow phenomenon by applying an advanced filter technique to the instantaneous flow fields. Accordingly, the characteristic flow structure in compound channels described by multiple authors- shear zone, secondary currents and high turbulence intensity - can be explained physically by the coherent structures. They also influence the turbulent energy budget by generating a strong production of turbulent kinetic energy within the interaction zone. This net generation of energy is distributed by secondary flows and turbulence fluctuations. The research presented in the thesis on hand could prove the existence of coherent turbulent structures in the shear zone of compound open channels. The appropriate experimental set-up as well as reliable methods have been developed for further studies. Especially a more detailed quantitative description of the structures themselves and also their temporal development are of interest. Based on these results, in the future coherent turbulent structures will be taken into consideration on a physical basis for dealing with practical water management tasks."],"dc:identifier":["https://publications.rwth-aachen.de/record/61483","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123144%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-5282"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:source":["Aachen : Publikationsserver der RWTH Aachen University XIV, 147 S. : Ill., graph. Darst. (2003). = Aachen, Techn. 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