Internal Heat Transfer and External Effectiveness Measurements for a Novel Turbine Blade Cooling Design

Efficiency and power output of gas turbines improve with an increase in turbine inlet temperatures, and blade designers continually seek out new methods of increasing these temperatures. Increases in turbine inlet temperatures are achieved by utilizing a combination of internal convective cooling and external film-cooling. This study will evaluate several novel cooling schemes for turbine airfoils, called microcircuits. Microcircuits are placed inside the turbine blade wall, and the features turbulate the air and increase heat transfer surface area, thereby augmenting convective cooling. The coolant flow then exits internal cooling passages to the external side of the blade. Here the coolant forms a protective layer along the external surface of the blade to protect the blade from the heated mainstream flow. In the current study, a low-speed large-scale wind tunnel facility was developed to measure internal heat transfer coefficients and external adiabatic effectiveness, using thermal liquid crystallography and infrared thermography. This test facility is unique in that it can be used to test the effects of internal cooling features on external film cooling. Results show that the highest augmentations in internal heat transfer were seen at the lowest Reynolds numbers. Internal features affected the shapes of external film-cooling contours, but the magnitudes of the spanwise averaged values did not change significantly with changes in internal geometry.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Mechanical Engineering

Department dc:contributor.department

Mechanical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2005

Author dc:creator

• Elder, Erin N.

Chair dc:contributor.committeechair

• Thole, Karen A.

Committee members dc:contributor.committeemember

• Ng, Wing Fai
• Dancey, Clinton L.

• microcircuit
• gas turbines
• Heat--Transmission
• film cooling
• internal cooling

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Dc Identifier Other

etd-05102005-130229

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/77004