Overall effectiveness, φ, for a simulated turbine blade leading edge was experimentally measured using a model constructed with a relatively high conductivity material selected so that the Biot number of the model matched engine conditions. The model incorporated three rows of cylindrical holes with the center row positioned on the stagnation line. Internally the model used an impingement cooling configuration. Overall effectiveness was measured for pitch variation from 7.6d to 11.6d for blowing ratios ranging from 0.5 to 3.0, and angle of attack from −7.7 deg to + 7.7 deg. Performance was evaluated for operation with a constant overall mass flow rate of coolant. Consequently when increasing the pitch, the blowing ratio was increased proportionally. The increased blowing ratio resulted in increased impingement cooling internally and increased convective cooling through the holes. The increased internal and convective cooling compensated, to a degree, for the decreased coolant coverage with increased pitch. Performance was evaluated in terms of laterally averaged φ, but also in terms of the minimum φ. The minimum φ evaluation revealed localized hot spots which are arguably more critical to turbine blade durability than the laterally averaged results. For small increases in pitch (from p/d = 7.6 to 9.6) there was only a small decrease in performance, but at p/d = 11.6 a significant reduction was observed.

References

References
1.
Bogard
,
D. G.
, and
Thole
,
K. A.
,
2006
, “
Gas Turbine Film Cooling
,”
J. Propul. Power
,
22
(
2
), pp.
249
270
.10.2514/1.18034
2.
Sen
,
B.
,
Schmidt
,
D. L.
, and
Bogard
,
D. G.
,
1996
, “
Film Cooling with Compound Angle Holes: Heat Transfer
,”
ASME J. Turbomach.
,
118
(
4
), pp.
800
807
.10.1115/1.2840937
3.
Albert
,
J. E.
,
Bogard
,
D. G.
, and
Cunha
,
F.
,
2004
, “
Adiabatic and Overall Effectiveness for a Film Cooled Blade
,”
ASME Turbo Expo
,
Vienna, Austria
, June 14–17,
ASME
Paper No. GT2004-53998.10.1115/GT2004-53998
4.
Harrison
,
K.
, and
Bogard
,
D.
,
2008
, “
Use of the Adiabatic Wall Temperature in Film Cooling to Predict Wall Heat Flux and Temperature
,” ASME Turbo Expo,
Berlin
, June 9–13,
ASME
Paper No. GT2008-51424.10.1115/GT2008-51424
5.
Mouzon
,
B. D.
,
Terrell
,
E. J.
,
Albert
,
J. E.
, and
Bogard
,
D. G.
,
2005
, “
Net Heat Flux Reduction and Overall Effectiveness for a Turbine Blade Leading Edge
,” ASME Turbo Expo,
Reno, NV
, June 6–9,
ASME
Paper No. GT2005-69002.10.1115/GT2005-69002
6.
Schmidt
,
D. L.
,
Sen
,
B.
, and
Bogard
,
D. G.
,
1996
, “
Film Cooling with Compound Angle Holes: Adiabatic Effectivess
,”
ASME J. Turbomach.
,
118
(
4
), pp.
807
814
.10.1115/1.2840938
7.
Pichon
,
Y.
,
2009
, “
Turbulence Field Measurements for the Small Wind Tunnel
,” TTCRL Internal Report,
The University of Texas at Austin
,
Austin, TX
.
8.
Johnson
,
R.
,
Maikell
,
J.
,
Bogard
,
D.
,
Piggush
,
J.
,
Kohli
,
A.
, and
Blair
,
M.
,
2009
, “
Experimental Study of the Effects of an Oscillating Approach Flow on Overall Cooling Performance of a Simulated Turbine Blade Leading Edge
,” ASME Turbo Expo,
Orlando, FL
, June 8–12,
ASME
Paper No. GT2009-60290.10.1115/GT2009-60290
9.
Moffat
,
R. J.
,
1985
, “
Using Uncertainty Analysis in the Planning of an Experiment
,”
ASME J. Fluids Eng.
,
107
(
2
), pp.
173
178
.10.1115/1.3242452
10.
Dobrowolski
,
L. D.
,
Bogard
,
D. G.
,
Piggush
,
J.
, and
Kohli
,
K.
,
2009
, “
Numerical Simulation of a Simulated Film Cooled Turbine Blade Leading Edge Including Heat Transfer Effects
,” ASME International Mechanical Engineering Congress & Exposition,
Lake Buena Vista, FL
, November 13–19,
ASME
Paper No. IMECE2009-11670.10.1115/IMECE2009-11670
11.
Dobrowolski
,
L. D.
,
2009
, “
Numerical Simulation of a Film Cooled Turbine Blade Leading Edge Including Heat Transfer Effects
,” M.S. thesis,
University of Texas at Austin
,
Austin, TX
.
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