{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/71095"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/71095","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Pressure and velocity fields in a relaxing three-dimensional turbulent boundary layer","abstract":"Static pressure and mean velocity data were obtained in a relaxing shear driven three-dimensional incompressible turbulent boundary layer flow produced by a swept rectangular step. The nominally 10 cm (4 in.) thick boundary layer had a freestream velocity of approximately 25 m/sec (80 ft/sec). The two steps investigated were each 3.8 cm (1.5 in.) high by 18.4 cm (7 .25 irt.) long and at angles of 30° and 45° to the transverse wind tunnel direction. Pressure gradients were determined by taking the derivative of least-squares curve fits to the static pressure data. Close to the trailing edge reattachment region, the maximum·gradient was·0.8 kPa/m (5 psf/f) for the 30° step and 0.4 kPa/m (2.5 psf/f) for the 45°step. As expected, a region of nominal pressure gradient (0.03 kPa/m or 0.2 psf/f compared to 1.6 kPa/m or 10 psf/f for a pressure driven flow) was found at greater than 36 cm (14 in.) down.stream of the trailing edge of each step. The wall crossflow angle decayed from 67° at 15 cm (6 in.) behind the trailing edge to 9° at 66 cm (26 in.) for the 30° step. In the same region, the crossflow angle decayed from 45° to 6° for the 45° step. The decay or relaxation was found to be much faster in the near-wall region and in the region close to the trailing edge. A defect in the streamwise velocity profiles indicated that the flow was dominated by the separation and reattachment over the step. For future shear driven investigations, a lower, more streamlined wing-type body is recommended to produce a moderately skewed boundary layer without dominant separation effects.","abstract_html":"Static pressure and mean velocity data were obtained in a relaxing shear driven three-dimensional incompressible turbulent boundary layer flow produced by a swept rectangular step. The nominally 10 cm (4 in.) thick boundary layer had a freestream velocity of approximately 25 m/sec (80 ft/sec). The two steps investigated were each 3.8 cm (1.5 in.) high by 18.4 cm (7 .25 irt.) long and at angles of 30° and 45° to the transverse wind tunnel direction. Pressure gradients were determined by taking the derivative of least-squares curve fits to the static pressure data. Close to the trailing edge reattachment region, the maximum·gradient was·0.8 kPa/m (5 psf/f) for the 30° step and 0.4 kPa/m (2.5 psf/f) for the 45°step. As expected, a region of nominal pressure gradient (0.03 kPa/m or 0.2 psf/f compared to 1.6 kPa/m or 10 psf/f for a pressure driven flow) was found at greater than 36 cm (14 in.) down.stream of the trailing edge of each step. The wall crossflow angle decayed from 67° at 15 cm (6 in.) behind the trailing edge to 9° at 66 cm (26 in.) for the 30° step. In the same region, the crossflow angle decayed from 45° to 6° for the 45° step. The decay or relaxation was found to be much faster in the near-wall region and in the region close to the trailing edge. A defect in the streamwise velocity profiles indicated that the flow was dominated by the separation and reattachment over the step. For future shear driven investigations, a lower, more streamlined wing-type body is recommended to produce a moderately skewed boundary layer without dominant separation effects.","abstract_has_math":false,"creators":["Nelson, Douglas J."],"institution":"Virginia Polytechnic Institute and State University","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Mechanical Engineering","degree_department":"Mechanical Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1979,"date_issued":"1979","date_published":"1979","updated_at":"2026-07-22T22:20:23Z","subjects":[],"languages":["en_US"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10919/71095","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Mechanical Engineering"]},{"key":"dc:creator","label":"Author","values":["Nelson, Douglas J."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2016-05-23T14:57:55Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2016-05-23T14:57:55Z"]},{"key":"dc:date.issued","label":"Date","values":["1979"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Polytechnic Institute and State University"]},{"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_US"]},{"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.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/71095"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Static pressure and mean velocity data were obtained in a relaxing shear driven three-dimensional incompressible turbulent boundary layer flow produced by a swept rectangular step. The nominally 10 cm (4 in.) thick boundary layer had a freestream velocity of approximately 25 m/sec (80 ft/sec). The two steps investigated were each 3.8 cm (1.5 in.) high by 18.4 cm (7 .25 irt.) long and at angles of 30° and 45° to the transverse wind tunnel direction. Pressure gradients were determined by taking the derivative of least-squares curve fits to the static pressure data. Close to the trailing edge reattachment region, the maximum·gradient was·0.8 kPa/m (5 psf/f) for the 30° step and 0.4 kPa/m (2.5 psf/f) for the 45°step. As expected, a region of nominal pressure gradient (0.03 kPa/m or 0.2 psf/f compared to 1.6 kPa/m or 10 psf/f for a pressure driven flow) was found at greater than 36 cm (14 in.) down.stream of the trailing edge of each step. The wall crossflow angle decayed from 67° at 15 cm (6 in.) behind the trailing edge to 9° at 66 cm (26 in.) for the 30° step. In the same region, the crossflow angle decayed from 45° to 6° for the 45° step. The decay or relaxation was found to be much faster in the near-wall region and in the region close to the trailing edge. A defect in the streamwise velocity profiles indicated that the flow was dominated by the separation and reattachment over the step. For future shear driven investigations, a lower, more streamlined wing-type body is recommended to produce a moderately skewed boundary layer without dominant separation effects."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Pressure and velocity fields in a relaxing three-dimensional turbulent boundary layer"]}]}],"canonical_facts":{"dc:contributor.department":["Mechanical Engineering"],"dc:creator":["Nelson, Douglas J."],"dc:date.accessioned":["2016-05-23T14:57:55Z"],"dc:date.available":["2016-05-23T14:57:55Z"],"dc:date.issued":["1979"],"dc:description.abstract":["Static pressure and mean velocity data were obtained in a relaxing shear driven three-dimensional incompressible turbulent boundary layer flow produced by a swept rectangular step. The nominally 10 cm (4 in.) thick boundary layer had a freestream velocity of approximately 25 m/sec (80 ft/sec). The two steps investigated were each 3.8 cm (1.5 in.) high by 18.4 cm (7 .25 irt.) long and at angles of 30° and 45° to the transverse wind tunnel direction. Pressure gradients were determined by taking the derivative of least-squares curve fits to the static pressure data. Close to the trailing edge reattachment region, the maximum·gradient was·0.8 kPa/m (5 psf/f) for the 30° step and 0.4 kPa/m (2.5 psf/f) for the 45°step. As expected, a region of nominal pressure gradient (0.03 kPa/m or 0.2 psf/f compared to 1.6 kPa/m or 10 psf/f for a pressure driven flow) was found at greater than 36 cm (14 in.) down.stream of the trailing edge of each step. The wall crossflow angle decayed from 67° at 15 cm (6 in.) behind the trailing edge to 9° at 66 cm (26 in.) for the 30° step. In the same region, the crossflow angle decayed from 45° to 6° for the 45° step. The decay or relaxation was found to be much faster in the near-wall region and in the region close to the trailing edge. A defect in the streamwise velocity profiles indicated that the flow was dominated by the separation and reattachment over the step. For future shear driven investigations, a lower, more streamlined wing-type body is recommended to produce a moderately skewed boundary layer without dominant separation effects."],"dc:description.degree":["Master of Science"],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/10919/71095"],"dc:language.iso":["en_US"],"dc:publisher":["Virginia Polytechnic Institute and State University"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["Pressure and velocity fields in a relaxing three-dimensional turbulent boundary layer"],"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":"2026-07-22T22:20:23Z"}