Abstract

A novel airfoil leading edge film cooling design has been investigated, and its performance over conventional alternatives quantified. In conventional designs, the region near the geometric stagnation line is typically between the two most upstream film hole rows, which each emit coolant in the downstream direction on their respective sides of the airfoil. This region is thus relatively starved of coolant flow and adequate cooling is achieved inefficiently with a high density of holes expelling a large amount of coolant in order to dilute the nearby mainstream flow. Drawing inspiration from recent literature on reverse-blowing film cooling holes, several film cooling geometries have been designed and tested with a view to improving upon this situation by blowing coolant from each side of the airfoil geometric stagnation line to the other in a criss-cross pattern. This is found to be capable of producing much higher film effectiveness near the stagnation line than a series of more conventional designs which were also tested, without decreasing downstream film effectiveness. A method is also described for using experimental film effectiveness data to estimate two novel measures of the efficiency of leading edge film coolant usage: the proportion of the mainstream which interacts with leading edge film coolant and the proportion of coolant from the two most upstream film hole rows which reaches the stagnation line.

References

References
1.
Fletcher
,
D. A.
,
1997
,
Internal Cooling of Turbine Blades: The Matrix Cooling Method
,
The University of Oxford
,
Oxford, UK
.
2.
Nowlin
,
S. R.
,
Gillespie
,
D. R. H.
,
Ireland
,
P. T.
,
Romero
,
E.
, and
Mitchell
,
M.
,
2007
, “
An Experimental and Computational Parametric Investigation of Flow Conditions in Intersecting Circular Passages
,”
ASME Turbo Expo 2007
, Vol.
4
,
Montreal, Canada
,
May 14–17
, pp.
849
859
, ASME Paper No. GT2007-28127.
3.
Li
,
X.
,
2010
, “
Numerical Simulation of Fluid Flow and Heat Transfer of Film Cooling With Backward Injection
,”
14th International Heat Transfer Conference
,
Washington, DC
,
Aug. 8–13
, ASME Paper No. IHTC14-22995.
4.
Shetty
,
S.
,
Li
,
X.
, and
Subbuswamy
,
G.
,
2012
, “
Numerical Simulation on Gas Turbine Film Cooling of Curved Surface With Backward Injection
,”
ASME 2012 Summer Heat Transfer Conference
,
Rio Grande, Puerto Rico
,
July 8–12
, pp.
1065
1072
, ASME Paper No. HT2012-58469.
5.
Subbuswamy
,
G.
,
Li
,
X.
, and
Gharat
,
K.
,
2013
, “
Numerical Simulation of Backward Film Cooling With Fan-Shaped Holes
,”
ASME 2013 Summer Heat Transfer Conference
,
Minneapolis, MN
,
July 14–19
, ASME Paper No. HT2013-17801.
6.
Chen
,
A. F.
,
Li
,
S.-J.
, and
Han
,
J.-C.
,
2014
, “
Film Cooling With Forward and Backward Injection for Cylindrical and Fan-Shaped Holes Using PSP Measurement Technique
,”
ASME Turbo Expo 2014
, Vol.
5B
,
Dusseldorf, Germany
,
June 16–20
, ASME Paper No. GT2014-26232.
7.
Park
,
S.
,
Jung
,
E. Y.
,
Kim
,
S. H.
,
Sohn
,
H.
, and
Cho
,
H. H.
,
2016
, “
Enhancement of Film Cooling Effectiveness Using Backward Injection Holes
,”
Int. J. Therm. Sci.
,
110
, pp.
314
324
. 10.1016/j.ijthermalsci.2016.08.001
8.
Prenter
,
R.
,
Hossain
,
M. A.
,
Agricola
,
L.
,
Ameri
,
A.
, and
Bons
,
J. P.
,
2017
, “
Experimental Characterization of Reverse-Oriented Film Cooling
,”
ASME Turbo Expo 2017
, Vol.
5C
,
Charlotte, NC
,
June 26–30
, ASME Paper No. GT2017-64731.
9.
Cresci
,
I.
,
Ireland
,
P. T.
,
Bacic
,
M.
,
Tibbott
,
I.
, and
Rawlinson
,
A.
,
2015
, “
Velocity and Turbulence Intensity Profiles Downstream of a Long Reach Endwall Double Row of Film Cooling Holes in a Gas Turbine Combustor Representative Environment
,”
ASME Turbo Expo 2015
, Vol.
2B
, ASME Paper No. GT2015-42307.
10.
Cresci
,
I.
,
Ireland
,
P. T.
,
Bacic
,
M.
,
Tibbott
,
I.
, and
Rawlinson
,
A.
,
2015
, “
Realistic Velocity and Turbulence Intensity Profiles at the Combustor-Turbine Interaction (CTI) Plane in a Nozzle Guide Vane Test Facility
,”
11th European Turbomachinery Conference
,
Madrid, Spain
,
Mar. 23–27
, Paper No. ETC2015-255.
11.
Pietrzyk
,
J. R.
,
Bogard
,
D. G.
, and
Crawford
,
M. E.
,
1990
, “
Effects of Density Ratio on the Hydrodynamics of Film Cooling
,”
ASME J. Turbomach.
,
112
(
3
), pp.
437
443
. 10.1115/1.2927678
12.
Drost
,
U.
, and
Bölcs
,
A.
,
1999
, “
Investigation of Detailed Film Cooling Effectiveness and Heat Transfer Distributions on a Gas Turbine Airfoil
,”
ASME J. Turbomach.
,
121
(
2
), pp.
233
242
. 10.1115/1.2841306
13.
Holgate
,
N. E.
,
Ireland
,
P. T.
, and
Romero
,
E.
,
2019
, “
The Effects of Combustor Cooling Features on Nozzle Guide Vane Film Cooling Experiments
,”
ASME J. Turbomach.
,
141
(
1
), p.
011005
. 10.1115/1.4041467
14.
Saumweber
,
C.
,
Schulz
,
A.
, and
Wittig
,
S.
,
2003
, “
Free-Stream Turbulence Effects on Film Cooling With Shaped Holes
,”
ASME J. Turbomach.
,
125
(
1
), pp.
65
73
. 10.1115/1.1515336
15.
Association Française de Normalisation
,
2003
,
Measurement of Fluid Flow by Means of Pressure Differential Devices Inserted in Circular Cross-section Conduits Running Full — Part 2: Orifice Plates
.
16.
Ravelli
,
S.
, and
Barigozzi
,
G.
,
2017
, “
Comparison of RANS and Detached Eddy Simulation Modeling Against Measurements of Leading Edge Film Cooling on a First-Stage Vane
,”
ASME J. Turbomach.
,
139
(
5
), p.
051005
. 10.1115/1.4035161
17.
Yepuri
,
G. B.
,
Talanki Puttarangasetty
,
A. B.
,
Kolke
,
D. K.
, and
Jesuraj
,
F.
,
2018
, “
Effect of RANS-Type Turbulence Models on Adiabatic Film Cooling Effectiveness Over a Scaled Up Gas Turbine Blade Leading Edge Surface
,”
J. Inst. Eng. Ser. C
,
99
(
4
), pp.
393
400
. 10.1007/s40032-016-0302-5
18.
Bogard
,
D. G.
, and
Thole
,
K. A.
,
2006
, “
Gas Turbine Film Cooling
,”
J. Propul. Power
,
22
(
2
), pp.
249
270
. 10.2514/1.18034
19.
Holgate
,
N. E.
,
Cresci
,
I.
,
Ireland
,
P. T.
, and
Rawlinson
,
A.
,
2017
, “
Prediction and Augmentation of Nozzle Guide Vane Film Cooling Hole Pressure Margin
,”
12th European Turbomachinery Conference
,
Stockholm, Sweden
,
Apr. 3–7
, Paper No. ETC2017-128.
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