Experiments were performed to study the combined effect of grid turbulence and unsteady wake on film effectiveness and heat transfer coefficient of a turbine blade model. Tests were done on a five-blade linear cascade at the chord Reynolds number of 3.0 × 105 at cascade inlet. Several combinations of turbulence grids, their locations, and unsteady wake strengths were used to generate various upstream turbulence conditions. The test blade had three rows of film holes in the leading edge region and two rows each on the pressure and suction surfaces. Air and CO2 were used as injectants. Results show that Nusselt numbers for a blade with film injection are much higher than that without film holes. An increase in mainstream turbulence level causes an increase in Nusselt numbers and a decrease in film effectiveness over most of the blade surface, for both density injectants, and at all blowing ratios. A free-stream turbulence superimposed on an unsteady wake significantly affects Nusselt numbers and film effectiveness compared with only an unsteady wake condition.

Issue Section:
Research Papers
Topics:
Blades, Carbon dioxide, Gas turbines, Heat transfer coefficients, Turbulence, Wakes, Cascades (Fluid dynamics), Chords (Trusses), Density, Pressure, Reynolds number, Suction, Turbine blades
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ASME JOURNAL OF TURBOMACHINERY
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2.
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M. F.
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R. P.
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,”
ASME JOURNAL OF TURBOMACHINERY
, Vol.
111
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87
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96
.
5.
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,
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,
1989
b, “
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ASME JOURNAL OF TURBOMACHINERY
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111
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103
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6.
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ASME JOURNAL OF TURBOMACHINERY
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116
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3
.
7.
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C.
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T.
,
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, “
An Experimental Convective Heat Transfer Investigation Around a Film-Cooled Gas Turbine Blade
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ASME JOURNAL OF TURBOMACHINERY
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112
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497
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503
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8.
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107
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13.
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14.
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755
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16.
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Influence of Unsteady Wake on Heat Transfer Coefficient From a Gas Turbine Blade
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ASME Journal of Heat Transfer
, Vol.
115
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911
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17.
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Film Cooling of a Gas Turbine Blade
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18.
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ASME JOURNAL OF TURBOMACHINERY
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20.
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21.
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22.
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Unsteady Wake Effect on Film Effectiveness and Heat Transfer Coefficient From a Turbine Blade With One Row of Air and CO2 Film Injection
,”
ASME Journal of Heat Transfer
, Vol.
116
, pp.
921
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928
.
23.
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,
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, “
Unsteady Wake Over a Linear Turbine Blade Cascade With Air and CO2 Film Injection: Part I—Effect on Heat Transfer Coefficients
,”
ASME JOURNAL OF TURBOMACHINERY
, Vol.
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, pp.
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.
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, and
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,”
ASME Journal of Engineering for Gas Turbines and Power
, Vol.
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137
.
25.
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,
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,
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, and
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,
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, “
Film Cooling on a Gas Turbine Rotor Blade
,”
ASME JOURNAL OF TURBOMACHINERY
, Vol.
114
, pp.
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.
26.
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,
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, and
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, “
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,”
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, Vol.
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.
27.
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, and
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,
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, “
Combined Effect of Free-Stream Turbulence and Unsteady Wake on Heat Transfer Coefficients From a Gas Turbine Blade
,”
ASME Journal of Heat Transfer
, Vol.
117
, pp.
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302
.
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