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dc.contributor.authorMcGlumphy, Jonathanen_US
dc.date.accessioned2014-03-14T20:06:52Z
dc.date.available2014-03-14T20:06:52Z
dc.date.issued2008-06-15en_US
dc.identifier.otheretd-01252008-143703en_US
dc.identifier.urihttp://hdl.handle.net/10919/26039
dc.description.abstractThe tandem airfoil has potential to do more work as a compressor blade than a single airfoil without incurring significantly higher losses. Although tandem blades are sometimes employed as stators, they have not been used in any known commercial rotors. The goal of this work is to evaluate the aerodynamic feasibility of using a tandem rotor in the rear stages of a core compressor. As such, the results are constrained to shock-free, fully turbulent flow. The work is divided into 2-D and 3-D simulations. The 3-D results are subject to an additional constraint: thick endwall boundary layers at the inlet. Existing literature data on tandem airfoils in 2-D rectilinear cascades have been compiled and presented in a Lieblein loss versus loading correlation. Large scatter in the data gave motivation to conduct an extensive 2-D CFD study evaluating the overall performance as a function of the relative positions of the forward and aft airfoils. CFD results were consistent with trends in the open literature, both of which indicate that a properly designed tandem airfoil can outperform a comparable single airfoil on- and off-design. The general agreement of the CFD and literature data serves as a validation for the computational approach. A high hub-to-tip ratio 3-D blade geometry was developed based upon the best-case tandem airfoil configuration from the 2-D study. The 3-D tandem rotor was simulated in isolation in order to scrutinize the fluid mechanisms of the rotor, which had not previously been well documented. A geometrically similar single blade rotor was also simulated under the same conditions for a baseline comparison. The tandem rotor was found to outperform its single blade counterpart by attaining a higher work coefficient, polytropic efficiency and numerical stall margin. An examination of the tandem rotor fluid mechanics revealed that the forward blade acts in a similar manner to a conventional rotor. The aft blade is strongly dependent upon the flow it receives from the forward blade, and tends to be more three-dimensional and non-uniform than the forward blade.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartDissertation-JDM_021708_Ver2.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectgas turbineen_US
dc.subjectcompressoren_US
dc.subjecttandem airfoilen_US
dc.subjectcascadeen_US
dc.subjecthigh-loadingen_US
dc.subjecttandem bladeen_US
dc.subjectrotoren_US
dc.subjectcomputationalen_US
dc.titleNumerical Investigation of Subsonic Axial-Flow Tandem Airfoils for a Core Compressor Rotoren_US
dc.typeDissertationen_US
dc.contributor.departmentMechanical Engineeringen_US
dc.description.degreePh. D.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineMechanical Engineeringen_US
dc.contributor.committeechairNg, Faien_US
dc.contributor.committeememberO'Brien, Walter F. Jr.en_US
dc.contributor.committeememberDancey, Clinton L.en_US
dc.contributor.committeememberRagab, Saad A.en_US
dc.contributor.committeememberVlachos, Pavlos P.en_US
dc.contributor.committeememberWellborn, Stevenen_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-01252008-143703/en_US
dc.date.sdate2008-01-25en_US
dc.date.rdate2008-02-18
dc.date.adate2008-02-18en_US


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