Pressure and velocity fields in a relaxing three-dimensional turbulent boundary layer

dc.contributor.authorNelson, Douglas J.en
dc.contributor.departmentMechanical Engineeringen
dc.date.accessioned2016-05-23T14:57:55Zen
dc.date.available2016-05-23T14:57:55Zen
dc.date.issued1979en
dc.description.abstractStatic 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.en
dc.description.degreeMaster of Scienceen
dc.format.extentxi, 171, [2] leavesen
dc.format.mimetypeapplication/pdfen
dc.identifier.urihttp://hdl.handle.net/10919/71095en
dc.language.isoen_USen
dc.publisherVirginia Polytechnic Institute and State Universityen
dc.relation.isformatofOCLC# 5630085en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.lccLD5655.V855 1979.N458en
dc.subject.lcshTurbulent boundary layeren
dc.titlePressure and velocity fields in a relaxing three-dimensional turbulent boundary layeren
dc.typeThesisen
dc.type.dcmitypeTexten
thesis.degree.disciplineMechanical Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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