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dc.contributor.authorHarper, David Kenedaen_US
dc.date.accessioned2014-03-14T20:37:07Z
dc.date.available2014-03-14T20:37:07Z
dc.date.issued2000-05-04en_US
dc.identifier.otheretd-05162000-11450016en_US
dc.identifier.urihttp://hdl.handle.net/10919/32841
dc.description.abstractIn this thesis, the benefits of boundary layer control (BLC) in improving aerodynamic performance and engine stability were examined in a compact, serpentine inlet exhibiting flow separation. A 1/14-scale turbofan engine simulator provided the flow through the inlet. The inletâ s mass flow was measured to be 759 scfm (0.939 lbm/s) with an average throat Mach number of 0.23 when the simulator speed was 40 krpm. Boundary layer suction, blowing, and their combination were used to minimize the inletâ s flow separation. The effectiveness of the suction alone and the blowing alone was shown to be approximately equivalent, and the effectiveness of the combined use of both was seen to be better than either one by itself. With blowing and suction flowrates around 1% of the simulatorâ s core flow, the inletâ s distortion was lowered by 40.5% (from 1.55% to 0.922%) while the pressure recovery was raised by 9.7% (from 87.2% to 95.6%). With its reduction in distortion, BLC was shown to allow the simulator to steadily operate in a range that would have otherwise been unstable. Minimizing the flow separation within the inlet was shown to directly relate to measurements from flush-mounted microphones along the inlet wall: as the exit distortion decreased the microphone spectrum also decreased in magnitude. The strong relationship between the aerodynamic profiles and the microphone signal suggests that microphones may be used in an active flow control scheme, where the BLC effort can be tailored for different engine operating conditions. Unfortunately, the sensing scheme used in this experiment showed the microphone signal to continue to decrease even when the separation is overly compensated; therefore refinements must be made before it would be practical in a real application.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartHarper_etd.pdfen_US
dc.rightsI hereby grant to Virginia Tech or its agents the right to archive and to make available my thesis or dissertation in whole or in part in the University Libraries in all forms of media, now or hereafter known. I retain all proprietary rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation.en_US
dc.subjectSerpentine inleten_US
dc.subjectwall-pressure fluctuationsen_US
dc.subjectBoundary layer controlen_US
dc.subjectSeparationen_US
dc.titleBoundary Layer Control and Wall-Pressure Fluctuations in a Serpentine Inleten_US
dc.typeThesisen_US
dc.contributor.departmentMechanical Engineeringen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineMechanical Engineeringen_US
dc.contributor.committeememberDancey, Clinton L.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-05162000-11450016/en_US
dc.contributor.committeecochairBurdisso, Ricardo A.en_US
dc.contributor.committeecochairNg, Faien_US
dc.date.sdate2000-05-16en_US
dc.date.rdate2001-05-17
dc.date.adate2000-05-17en_US


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