Aerodynamic performance measurements of a fully scaled, film-coated, turbine stage

The MIT Blowdown Turbine short duration test facility was used to experimentally measure the aerodynamic performance of a film-cooled turbine stage. Turbine torque, speed, mass flow, temperature, and pressure were measured and used to calculate efficiency. Pressure ratio, corrected speed, and coolant mass flow were varied parametrically over a range of conditions and compared to a baseline. No distinct trend was seen in the pressure ratio tests. Efficiency increased approximately 2.2% with a corrected speed increase of 20%. This trend is a result of a corresponding decrease in blade loading. An efficiency decrease of 2% was shown for a two-fold increase in coolant mass flow. A preliminary comparison to a previous uncooled test series showed a 2% decrease in efficiency with a 12% coolant-to-mainstream mass flow ratio. To complete these tests, an uncooled turbine configuration was modified to a film-cooled configuration. A solid blade and nozzle guide vane set was machined via electro-discharge machining, laser drilling, and laser welding to provide film-cooling holes and manifold channels. The effective area (CdA) of the film-cooling holes was measured and part-to-part variations quantified. A coolant feed system was constructed to provide coolant flow to the turbine. Flow to the rotor blades, nozzle guide vanes, and tip casing was metered and controlled independently. Thick walled, squared edged, choked orifices were used. A set of experiments were performed to show that supersaturated coolant flow could be adequately controlled by this method.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Aeronautics and Astronautics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

1999

Author dc:creator

• Spadaccini, Christopher M. (Christopher Michael), 1974-

Advisor dc:contributor.advisor

• Gerald R. Guenette.

• Aeronautics and Astronautics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/50551

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/50551