Fan-Shaped Hole Film Cooling on Turbine Blade and Vane in a Transonic Cascade with High Freestream Turbulence: Experimental and CFD Studies

The contribution of present research work is to experimentally investigate the effects of blowing ratio and mainstream Mach number/Reynolds number (from 0.6/8.5X10⁵ to 1.0/1.4X10⁶) on the performance of the fan-shaped hole injected turbine blade and vane. The study was operated with high freestream turbulence intensity (12% at the inlet) and large turbulence length scales (0.26 for blade, 0.28 for vane, normalized by the cascade pitch of 58.4mm and 83.3mm respectively). Both convective heat transfer coefficient, in terms of Nusselt number, and adiabatic effectiveness are provided in the results. Present research work also numerically investigates the shock/film cooling interaction. A detailed analysis on the physics of the shock/film cooling interaction in the blade cascade is provided. The results of present research suggests the following major conclusions. Compared to the showerhead only vane, the addition of fan-shaped hole injection on the turbine Nozzle Guide Vane (NGV) increases the Net Heat Flux Reduction (NHFR) 2.6 times while consuming 1.6 times more coolant. For the blade, combined with the surface curvature effect, the increase of Mach number/Reynolds number results in an improved film cooling effectiveness on the blade suction side, but a compromised cooling performance on the blade pressure side. A quick drop of cooling effectiveness occurs at the shock impingement on the blade suction side near the trailing edge. The CFD results indicate that this adiabatic effectiveness drop was caused by the strong secondary flow after shock impingement, which lifts coolant away from the SS surface, and increases the mixing. This secondary flow is related to the spanwise non-uniform of the shock impingement.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Mechanical Engineering

Department dc:contributor.department

Mechanical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2012

Author dc:creator

• Xue, Song

Chairs dc:contributor.committeechair

• Ng, Wing Fai
• Ekkad, Srinath V.

Committee members dc:contributor.committeemember

• Tafti, Danesh K.
• Diller, Thomas E.
• Devenport, William J.
• Dancey, Clinton L.

• Film Cooling
• Gas Turbines
• curvature effect
• Heat--Transmission
• Computational fluid dynamics
• Shock effect
• Transonic Cascade

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-07242012-113420

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/77979