Experimental investigations were performed to measure the local heat transfer coefficient $(hg)$ distributions of film cooling over a flat blade under both stationary and rotating conditions. Film cooling was via a straight circular hole of 4 mm in diameter located in the middle section of the blade angled 30 deg along the streamwise direction and 90 deg along the spanwise direction. The Reynolds $(ReD)$ number based on the mainstream velocity and the film hole diameter was fixed at 3191, and the rotating speed $(ω)$ was either 0 rpm or 800 rpm; the film cooling blowing ratios ranged from 0.4 to 2.0, and two averaged density ratios of 1.02 and 1.53 were employed with air and carbon dioxide $(CO2)$ as the coolant, respectively. Thermochromic liquid crystal was used to measure the solid surface temperature distributions. Experimental results showed the following: (1) In the stationary case, the blowing ratio has a significant influence on the nondimensional heat transfer coefficient $(hg/h0)$ especially in the near hole region. (2) The film trajectory in rotation had an obvious deflection in the spanwise direction, and the deflection angles on the suction surface are larger than those on the pressure surface. This was attributed to the combined action of the Coriolis force and centrifugal force. (3) In the rotating case, for $CO2$ injection, the magnitude of heat transfer coefficient on the pressure surface is reduced compared with the stationary case, and the blowing ratio has smaller effects on $hg/h0$ distribution. However, on the suction surface, the heat transfer coefficient at $x/D<1.0$ is enhanced and then rapidly reduced to be also below the stationary values. For air injection, rotation also depresses the $hg/h0$ for both the pressure and the suction surface. (4) The density ratio shows a considerable effect on the streamwise heat transfer coefficient distributions especially for the rotating cases.

1.
Han
,
J. C.
,
Dutta
,
S.
, and
,
S. V.
, 2000,
Gas Turbine Heat Transfer and Cooling Technology
,
Taylor & Francis
,
New York
.
2.
Eriksen
,
V. L.
, and
Goldstein
,
R. J.
, 1974, “
Heat Transfer and Film Cooling Following Injection Through Inclined Tubes
,”
ASME J. Heat Transfer
,
96
, pp.
239
245
. 0022-1481
3.
Hay
,
N.
,
Lampard
,
D.
, and
Saluja
,
C. L.
, 1985, “
Effects of Cooling Films on the Heat Transfer Coefficient on a Flat Plate With Zero Mainstream Pressure Gradient
,”
ASME J. Eng. Gas Turbines Power
,
107
, pp.
105
110
. 0742-4795
4.
Lloyd
,
S.
, and
Brown
,
A.
, 1985, “
Fluid Flow and Heat Transfer Characteristics in the Entrance Region of Circular Pipes
,” ASME Paper No. 85-GT-120.
5.
Andrews
,
G. E.
,
,
M.
,
Asere
,
A. A.
,
Hussain
,
C. I.
,
Khoshkbar
,
M. S.
,
Azari
,
M. S.
, and
,
M. C.
, 1986, “
Small Diameter Film Cooling Holes: Wall Convective Heat Transfer
,”
ASME J. Turbomach.
,
108
, pp.
283
289
. 0889-504X
6.
Makki
,
Y. H.
, and
Jakubowski
,
G. S.
, 1986, “
An Experimental Study of Film Cooling From Diffused Trapezoidal Shaped Holes
,” AIAA Paper No. 86-1326.
7.
Hyams
,
D. G.
, and
Leylek
,
J. H.
, 1997, “
A Detailed Analysis of Film Cooling Physics—Part III: Streamwise Injection With Shaped Holes
,” ASME Paper No. 97-GT-271.
8.
,
S. V.
,
Du
,
H.
, and
Han
,
J. C.
, 1995, “
Local Heat Transfer Coefficient and Film Effectiveness Distributions on a Cylindrical Leading Edge Model Using a Transient Liquid Crystal Image Method
,”
ASME Winter Annual Meeting
, San Francisco, CA.
9.
Ou
,
S.
, and
Rivir
,
R. B.
, 2001, “
Leading Edge Film Cooling Heat Transfer With High Free Stream Turbulence Using a Transient Liquid Crystal Image Method
,”
Int. J. Heat Fluid Flow
,
22
, pp.
614
623
. 0142-727X
10.
Yu
,
Y.
,
Yen
,
C. -H.
,
Shih
,
T. I.-P.
,
Chyu
,
M. K.
, and
Gogineni
,
S.
, 2002, “
Film Cooling Effectiveness and Heat Transfer Coefficient Distributions Around Diffusion Shaped Holes
,”
ASME J. Heat Transfer
0022-1481,
124
, pp.
820
827
.
11.
Yuen
,
C. H. N.
, and
Martinez-Botas
,
R. F.
, 2003, “
Film Cooling Characteristics of a Single Round Hole at Various Streamwise Angles in a Crossflow—Part II: Heat Transfer Coefficients
,”
Int. J. Heat Mass Transfer
0017-9310,
46
, pp.
237
249
.
12.
Yuen
,
C. H. N.
, and
Martinez-Botas
,
R. F.
, 2005, “
Film Cooling Characteristics of Rows of Round Holes at Various Streamwise Angles in a Crossflow—Part II: Heat Transfer Coefficients
,”
Int. J. Heat Mass Transfer
,
48
, pp.
5017
5035
. 0017-9310
13.
Abhari
,
R. S.
, and
Epstein
,
A. H.
, 1994, “
An Experimental Study of Film Cooling in a Rotating Transonic Turbine
,”
ASME J. Turbomach.
0889-504X,
116
, pp.
63
70
.
14.
Kline
,
S. J.
, and
McClintock
,
F. A.
, 1953, “
Describing Uncertainties in Single-Sample Experiments
,”
Mech. Eng. (Am. Soc. Mech. Eng.)
,
75
, pp.
3
8
. 0025-6501
15.
Ammari
,
H. D.
,
Hay
,
N.
, and
Lampard
,
D.
, 1990, “
The Effect of Density Ratio on the Heat Transfer Coefficient From a Film Cooled Flat Plate
,”
ASME J. Turbomach.
0889-504X,
112
, pp.
444
450
.