Aerodynamics of Endwall Contouring with Discrete Holes and an Upstream Purge Slot Under Transonic Conditions  with and without Blowing

dc.contributor.authorBlot, Dorian Matthewen
dc.contributor.committeechairEkkad, Srinath V.en
dc.contributor.committeechairNg, Wing Faien
dc.contributor.committeememberO'Brien, Walter F. Jr.en
dc.contributor.departmentMechanical Engineeringen
dc.date.accessioned2013-02-19T22:41:10Zen
dc.date.available2013-02-19T22:41:10Zen
dc.date.issued2013-01-23en
dc.description.abstractEndwall contouring has been widely studied as an effective measure to improve aerodynamic performance by reducing secondary flow strength. The effects of endwall contouring with discrete holes and an upstream purge slot for a high turning (127") airfoil passage under transonic conditions are investigated. The total pressure loss and secondary flow field were measured for two endwall geometries. The non-axisymmetric endwall was developed through an optimization study [1] to minimize secondary losses and is compared to a baseline planar endwall. The blade inlet span increased by 13 degrees with respect to the inlet in order to match engine representative inlet/exit Mach number loading in a HP turbine.  The experiments were performed in a quasi-2D linear cascade with measurements at design exit Mach number 0.88 and incidence angle. Four cases were analyzed for each endwall -- the effect of slot presence (with/without coolant) and the effect of discrete holes (with/without coolant) without slot injection. The coolant to mainstream mass flow ratio was set at 1.0% and 0.25% for upstream purge slot and discrete holes, respectively.  Aerodynamic loss coefficient is calculated with the measured exit total pressure at 0.1 Cax downstream of the blade trailing edge. CFD studies were conducted in compliment. The aero-optimized endwall yielded lower losses than baseline without the presence of the slot. However, in presence of the slot, losses increased due to formation of additional vortices. For both endwall geometries, results reveal that the slot has increased losses, while the addition of coolant further influences secondary flow development.en
dc.description.degreeMaster of Scienceen
dc.format.mediumETDen
dc.identifier.othervt_gsexam:159en
dc.identifier.urihttp://hdl.handle.net/10919/19257en
dc.publisherVirginia Techen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectGas Turbinesen
dc.subjectTransonic Cascadeen
dc.subjectAerodynamics. Heat Transferen
dc.subjectFilm Coolingen
dc.subjectUpstream Purge Sloten
dc.subjectDiscrete Hole Coolingen
dc.subjectEndwallen
dc.titleAerodynamics of Endwall Contouring with Discrete Holes and an Upstream Purge Slot Under Transonic Conditions  with and without Blowingen
dc.typeThesisen
thesis.degree.disciplineMechanical Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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